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Thread: PCM or not wired right

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  1. #1
    Join Date
    May 2008
    Location
    Kentucky
    Posts
    144

    PCM or not wired right

    Checklist that we have done and is working.
    1) Checked all grounds and power pins on pcm---- all good.
    2) Getting power and ground to coil packs but no spark.
    3) Relay from nelson harness clicks which ignition key is turned. Which is supposed to.
    4) Fuel pump is working and getting pressure.

    The following pins didn't get any power in off/run/crank
    C2 Pin 59 Crank voltage
    C1 Pin 12 CKP sensor signal
    C1 Pin 39 Starter enable relay control

    Is there any way to test the coil packs to make sure there good?
    Also how would I go about testing the cam and crank sensor making sure there working?

    Is there anything else I should check or is there something in the PCM that should have been turned off that wasn't?


    Ok I hooked up one of those general scan tools and this is what it came up with a codes:
    1) P0120 TPS/Pedal Position Sensor A circuit malfunction
    2) P0220 TPS/Pedal Position Sensor B circuit malfunction
    3) P1516 Manf Contr Speed Idle Speed control auxiliary inputs
    4) P1518 Manf Contr Speed Idle Speed control auxiliary inputs

    I have DBW pedal
    So like a throttle position sensor is it possible the pedal position sensor on the side of the throttle body bad? Also shouldn't once the key is on the throttle work with the pedal?

    Travis
    Last edited by 468Blazer; 08-10-2008 at 11:40 AM.
    1996 GMC extended cab, 2003 5.3/auto

  2. #2
    Join Date
    May 2004
    Posts
    2,120
    I know this has probably already been asked but is the PCM and TAC module from the same vehicle? If not this could be the problem.


    97 GMC, 2002 LS6.

    1991 GMC Syclone #1428

  3. #3
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    May 2008
    Location
    Kentucky
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    144
    drive by wire pedal is not from the same exact vehicle, as the engine/computer. The junkyard supposedly took the pedal and module out of a 03 silverado they had.
    Last edited by 468Blazer; 08-10-2008 at 11:51 AM.
    1996 GMC extended cab, 2003 5.3/auto

  4. #4
    Join Date
    May 2004
    Posts
    2,120
    They have to match or it won't start. If it came out of the same vehicle life would be great but there's no telling what they gave you.


    With you getting these codes below I wonder if the module is bad or not the right one for the pcm. Look at all of your wiring real well to make sure one of crimps aren't loose or damaged. You might have to get another module. I could understand 1 bad coil but not all of them. Hell the LS1 will run without a spark plug hood up, just slightly rough.

    1) P0120 TPS/Pedal Position Sensor A circuit malfunction
    2) P0220 TPS/Pedal Position Sensor B circuit malfunction


    97 GMC, 2002 LS6.

    1991 GMC Syclone #1428

  5. #5
    Join Date
    May 2008
    Location
    Kentucky
    Posts
    144
    well I ran the #'s on the TAC module and it is from a 03-04 vehicle. I'm going to order a accelerator pedal sensor and see if this will fix it. I would say more than likely it would be the sensor instead of the whole module. Guess we will see.
    1996 GMC extended cab, 2003 5.3/auto

  6. #6
    Join Date
    May 2004
    Posts
    2,120
    you might be right but you should be able to check ohms and voltage to the sensor to see if your getting a signal.


    97 GMC, 2002 LS6.

    1991 GMC Syclone #1428

  7. #7
    If the harness came with some kinda instructions, this might have been realized sooner than later.
    LSX conversions, so easy a caveman can do it.

  8. #8
    Join Date
    Mar 2008
    Location
    Denver, Colorado
    Posts
    60
    it is hard to read i can ax this to you if you need it.
    i had the same issue with my swap turned out that when they cut the wires out of donor truck and i soldered them back together it had a cold joint. i resoldered them and problem resolved.

    hope this helps a little bit


    DTC P0120
    Circuit Description
    The throttle position (TP) sensor 1 is a potentiometer type sensor with the following circuits:

    • A 5-volt reference circuit

    • A low reference circuit

    • A signal circuit

    The TP sensor is used to determine the throttle plate angle for various engine management systems. The control module provides the TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensor then provides the control module a signal voltage proportional to throttle plate movement. TP sensor 1 signal voltage is low at closed throttle and increases as the throttle opens. When the control module detects that the TP sensor 1 signal or TP sensor 5-volt reference voltage is outside the predetermined range, this DTC sets.

    Conditions for Running the DTC
    • DTCs P2108 or U0107 are not set.

    • The ignition switch is in the Crank or Run position.

    • The ignition voltage is more than 5.23 volts.

    Conditions for Setting the DTC
    • The TP sensor 1 signal voltage is less than 0.37 volt or more than 4.51 volts.

    • The above condition is present for more than 1 second.

    Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.

    • The control module commands the TAC system to operate in the Reduced Engine Power mode.

    • A message center or an indicator displays Reduced Engine Power.

    • Under certain conditions the control module commands the engine OFF.

    Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

    • Clear the MIL and the DTC with a scan tool.

    Diagnostic Aids
    • Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs could be set with no circuit or component conditions found during diagnostic testing.

    • When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture Info.

    • If this DTC is determined to be intermittent, refer to Intermittent Conditions .

    Test Description
    The number below refers to the step number on the diagnostic table.

    When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture Info.

    Step
    Action
    Values
    Yes
    No

    Schematic Reference: Engine Controls Schematics

    Connector End View Reference: Engine Controls Component Views or Powertrain Control Module Connector End Views

    1
    Did you perform the Diagnostic System Check - Engine Controls?
    --
    Go to Step 2
    Go to Diagnostic System Check - Engine Controls

    2
    Turn OFF the ignition.
    Remove the air inlet duct from the throttle body.
    Disconnect the throttle body harness connector.
    Connect the jumper wires between the throttle position (TP) sensor 1 terminals of the throttle body harness connector and the corresponding TP sensor 1 terminals of the throttle body.
    Turn ON the ignition, with the engine OFF.
    Close the throttle blade by hand.
    Observe the TP sensor 1 voltage with a scan tool.
    Is the TP sensor 1 voltage within the specified range?
    0.37-0.71 V
    Go to Step 5
    Go to Step 3

    3
    Turn OFF the ignition.
    Connect jumper wires between the TP sensor 2 terminals of the throttle body harness connector and the corresponding TP sensor 2 terminals of the throttle body.
    Turn ON the ignition, with the engine OFF.
    Close the throttle blade by hand.
    Observe the TP sensor 2 voltage with a scan tool.
    Is the TP sensor 2 voltage within the specified range?
    0.28-0.81 V
    Go to Step 9
    Go to Step 4

    4
    Is DTC U0107 also set?
    --
    Go to Diagnostic Trouble Code (DTC) List
    Go to Step 9

    5
    Open the throttle blade to wide open throttle (WOT) by hand.
    Observe the TP sensor 1 voltage parameter on the scan tool.
    Is the TP sensor 1 voltage parameter more than the specified value?
    4.51 V
    Go to Step 9
    Go to Step 6

    6
    Disconnect the TP sensor harness connector.
    Disconnect the throttle actuator control (TAC) module harness connector containing the TP sensor circuits.
    Test the TP sensor low-reference circuit for a short to ground with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 7

    7
    Turn OFF the ignition for 15 seconds.
    Connect the TAC module harness connector.
    Connect the throttle body harness connector.
    Install the air inlet duct.
    Turn ON the ignition, with the engine OFF.
    Select the DTC Info option on the scan tool.
    Lightly touch and move the related engine wiring harnesses and connectors for the TP sensor while observing the DTC Info. The DTC will set if an intermittent condition is present. Refer to Connector Repairs and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 8

    8
    Continue to observe the DTC Info.
    Slowly depress the accelerator pedal to WOT, then slowly return the pedal to the released position 3 times.
    Does the scan tool indicate this DTC failed this ignition?
    --
    Go to Step 27
    Go to Diagnostic Aids

    9
    Disconnect the TP sensor harness connector.
    Measure the voltage at the TP sensor 1 signal circuit with a DMM connected to ground.
    Is the voltage within the specified range?
    3.94-6.06 V
    Go to Step 14
    Go to Step 10

    10
    Turn OFF the ignition.
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Turn ON the ignition, with the engine OFF.
    Test the TP sensor 1 signal circuit for a short to voltage with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 11

    11
    Test the TP sensor 1 signal circuit for an open or high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 12

    12
    Test the TP sensor 1 signal circuit for a short to ground with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 13

    13
    Disconnect the other TAC module harness connector.
    Test for a short between the TP sensor 1 signal circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 28

    14
    Measure the voltage from the TP sensor 1 5-volt reference circuit to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

    Is the voltage within the specified range?
    4.54-5.21 V
    Go to Step 24
    Go to Step 15

    15
    Is the voltage more than the specified value?
    5.21 V
    Go to Step 16
    Go to Step 18

    16
    Turn OFF the ignition.
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Turn ON the ignition, with the engine OFF.
    Test the TP sensor 1 5-volt reference circuit for a short to voltage with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 17

    17
    Turn OFF the ignition.
    Disconnect the accelerator pedal position (APP) sensor harness connector.
    Disconnect the other TAC module harness connector.
    Turn ON the ignition, with the engine OFF.
    Test the APP sensor 1 5-volt reference circuit for a short to voltage with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 22

    18
    Disconnect the APP sensor.

    Is the voltage less than the specified value?
    4.54 V
    Go to Step 19
    Go to Step 30

    19
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Test the TP sensor 1 5-volt reference circuit for an open or high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 20

    20
    Test the TP sensor 1 5-volt reference circuit for a short to ground with a DMM.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 21

    21
    Test the APP sensor 1 5-volt reference circuit for a short to ground with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 22

    22
    Test for a short between the TP sensor 1 5-volt reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 23

    23
    Test for a short between the APP sensor 1 5-volt reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 28

    24
    Connect a fused jumper between the TP sensor 1 low reference circuit and the TP sensor 1 signal circuit.
    Observe the TP sensor 1 voltage parameter with a scan tool.
    Is the TP sensor 1 parameter near the specified value?
    0 V
    Go to Step 26
    Go to Step 25

    25
    Turn OFF the ignition.
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Test the TP sensor 1 low-reference circuit for an open or high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 28

    26
    Inspect for an intermittent and for a poor connection at the throttle body harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 29

    27
    Inspect for an intermittent and for a poor connection at the APP sensor harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 30

    28
    Inspect for an intermittent and for a poor connection at the TAC module harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 32
    Go to Step 31

    29
    Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .

    Did you complete the replacement?
    --
    Go to Step 32
    --

    30
    Replace the APP sensor. Refer to Accelerator Pedal Position Sensor Replacement .

    Did you complete the replacement?
    --
    Go to Step 32
    --

    31
    Replace the TAC module. Refer to Electronic Throttle Actuator Control Module Replacement .

    Did you complete the replacement?
    --
    Go to Step 32
    --

    32
    Clear the DTCs with a scan tool.
    Turn OFF the ignition for 30 seconds.
    Start the engine.
    Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
    Did the DTC fail this ignition?
    --
    Go to Step 2
    Go to Step 33

    33
    Observe the Capture Info with a scan tool.

    Are there any DTCs that have not been diagnosed?


    DTC P0220
    Circuit Description
    The throttle position (TP) sensor 2 is a potentiometer type sensor with the following circuits:

    • A 5-volt reference circuit

    • A low reference circuit

    • A signal circuit

    The TP sensor is used to determine the throttle plate angle for various engine management systems. The control module provides the TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensor then provides the control module a signal voltage proportional to throttle plate movement. The TP sensor 1 signal voltage is low at closed throttle and increases as the throttle opens. When the control module detects that the TP sensor 2 signal or the TP sensor 5-volt reference voltage is outside the predetermined range, this DTC sets.

    Conditions for Running the DTC
    • DTCs P2108 or U0107 are not set.

    • The ignition switch is in the Crank or Run position.

    • The ignition voltage is more than 5.23 volts.

    Conditions for Setting the DTC
    • The TP sensor 2 voltage is less than 0.28 volt or greater than 4.60 volts.

    • The above condition is present for more than 1 second.

    Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.

    • The control module commands the TAC system to operate in the Reduced Engine Power mode.

    • A message center or an indicator displays Reduced Engine Power.

    • Under certain conditions the control module commands the engine OFF.

    Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

    • Clear the MIL and the DTC with a scan tool.

    Diagnostic Aids
    • Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.

    • When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.

    • If this DTC is determined to be intermittent, refer to Intermittent Conditions .

    Test Description
    The number below refers to the step number on the diagnostic table.

    When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture Info.

    Step
    Action
    Values
    Yes
    No

    Schematic Reference: Engine Controls Schematics

    Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views

    1
    Did you perform the Diagnostic System Check - Engine Controls?
    --
    Go to Step 2
    Go to Diagnostic System Check - Engine Controls

    2
    Turn OFF the ignition.
    Remove the air inlet duct from the throttle body.
    Disconnect the throttle body harness connector.
    Connect jumper wires between the throttle position (TP) sensor 2 terminals of the throttle body harness connector and the corresponding TP sensor 2 terminals of the throttle body.
    Turn ON the ignition, with the engine OFF.
    Close the throttle blade by hand.
    Observe the TP sensor 2 voltage with a scan tool.
    Is the TP sensor 2 voltage within the specified range?
    0.28-0.81 V
    Go to Step 3
    Go to Step 7

    3
    Open the throttle blade to wide open throttle (WOT) by hand.
    Observe the TP sensor 2 voltage parameter on the scan tool.
    Is the TP sensor 2 voltage parameter more than the specified value?
    4.60 V
    Go to Step 7
    Go to Step 4

    4
    Disconnect the TP sensor harness connector.
    Disconnect the throttle actuator control (TAC) module harness connector containing the TP sensor circuits.
    Test the TP sensor low-reference circuit for a short to ground with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 5

    5
    Turn OFF the ignition for 15 seconds.
    Connect the TAC module harness connector.
    Connect the throttle body harness connector.
    Install the air inlet duct.
    Turn ON the ignition, with the engine OFF.
    Select the DTC Info option on the scan tool.
    Lightly touch and move the related engine wiring harnesses and connectors for the TP sensor while observing the DTC Info. The DTC will set if an intermittent condition is present. Refer to Connector Repairs and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 6

    6
    Continue to observe the DTC Info.
    Slowly depress the accelerator pedal to WOT, then slowly return the pedal to the released position 3 times.
    Does the scan tool indicate this DTC failed this ignition?
    --
    Go to Step 25
    Go to Diagnostic Aids

    7
    Disconnect the TP sensor harness connector.
    Measure the voltage at the TP sensor 2 signal circuit with a DMM connected to ground.
    Is the voltage within the specified range?
    3.94-6.06 V
    Go to Step 12
    Go to Step 8

    8
    Turn OFF the ignition.
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Turn ON the ignition, with the engine OFF.
    Test the TP sensor 2 signal circuit for a short to voltage with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 9

    9
    Test the TP sensor 2 signal circuit for an open or high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 10

    10
    Test the TP sensor 2 signal circuit for a short to ground with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 11

    11
    Disconnect the other TAC module harness connector.
    Test for a short between the TP sensor 2 signal circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 26

    12
    Measure the voltage from the TP sensor 2 5-volt reference circuit to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

    Is the voltage within the specified range?
    4.54-5.21 V
    Go to Step 22
    Go to Step 13

    13
    Is the voltage more than the specified value?
    5.21 V
    Go to Step 14
    Go to Step 16

    14
    Turn OFF the ignition.
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Turn ON the ignition, with the engine OFF.
    Test the TP sensor 2 5-volt reference circuit for a short to voltage with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 15

    15
    Turn OFF the ignition.
    Disconnect the accelerator pedal position (APP) sensor harness connector.
    Disconnect the other TAC module harness connector.
    Turn ON the ignition, with the engine OFF.
    Test the APP sensor 2 5-volt reference circuit for a short to voltage with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 20

    16
    Disconnect the APP sensor.

    Is the voltage less than the specified value?
    4.54 V
    Go to Step 17
    Go to Step 28

    17
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Test the TP sensor 2 5-volt reference circuit for an open or high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 18

    18
    Test the TP sensor 2 5-volt reference circuit for a short to ground with a DMM.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 19

    19
    Test the APP sensor 2 5-volt reference circuit for a short to ground with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 20

    20
    Test for a short between the TP sensor 2 5-volt reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 21

    21
    Test for a short between the APP sensor 2 5-volt reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 26

    22
    Connect a fused jumper between the TP sensor 2 low-reference circuit and the TP sensor 2 signal circuit.
    Observe the TP sensor 2 voltage parameter with a scan tool.
    Is the TP sensor 2 parameter near the specified value?
    0 V
    Go to Step 24
    Go to Step 23

    23
    Turn OFF the ignition.
    Disconnect the TAC module harness connector containing the TP sensor circuits.
    Test the TP sensor 2 low-reference circuit for an open or high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 26

    24
    Inspect for an intermittent and for a poor connection at the throttle body harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 27

    25
    Inspect for an intermittent and for a poor connection at the APP sensor harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 28

    26
    Inspect for an intermittent and for a poor connection at the TAC module harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

    Did you find and correct the condition?
    --
    Go to Step 30
    Go to Step 29

    27
    Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .

    Did you complete the replacement?
    --
    Go to Step 30
    --

    28
    Replace the APP sensor. Refer to Accelerator Pedal Position Sensor Replacement .

    Did you complete the replacement?
    --
    Go to Step 30
    --

    29
    Replace the TAC module. Refer to Electronic Throttle Actuator Control Module Replacement .

    Did you complete the replacement?
    --
    Go to Step 30
    --

    30
    Clear the DTCs with a scan tool.
    Turn OFF the ignition for 30 seconds.
    Start the engine.
    Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
    Did the DTC fail this ignition?
    --
    Go to Step 2
    Go to Step 31

    31
    Observe the Capture Info with a scan tool.

    Are there any DTCs that have not been diagnosed?

  9. #9
    Join Date
    May 2008
    Location
    Kentucky
    Posts
    144
    wow. lol. It may take me a bit to read this over and over and over but I really appreciate it. I'll check things out in the morning.
    1996 GMC extended cab, 2003 5.3/auto

  10. #10
    Join Date
    May 2008
    Location
    Kentucky
    Posts
    144
    Well recieved my accelerator pedal position sensor and replaced it. Now my throttle does work once pushed but still getting the same trouble codes.
    1996 GMC extended cab, 2003 5.3/auto

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