Home/GMC/Envoy/GMC Envoy II (2001-2009)/Repair manual/Testing & Diagnostics/Engine Control System - 5.3L - DTC P1516 to P3449: Overview
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Engine Control System - 5.3L - DTC P1516 to P3449: Overview GMC Envoy II

Testing & Diagnostics ~1859 words

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 8: The throttle valve is spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
  2. 11: When the ignition is turned ON, the ECM operates the throttle control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Are DTCs P0120, P0220, P2120, P2125, P2135, P2138 also set?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 3
3IMPORTANT: The throttle angle and pedal angle may not correspond during this procedure. Turn ON the ignition, with the engine OFF. Observe the throttle position (TP) sensor 1 and 2 angle parameters. Apply and release the accelerator pedal several times. Does the TP sensor 1 and 2 angle parameters increase as the pedal is applied and decrease as the pedal is released?Go to Step 4Go to Step 5
4Observe the Freeze Frame/Failure Records for this DTC. 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 5Go to Diagnostic Aids
5Turn ON the ignition, with the engine OFF. Probe both sides of the TAC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 6Go to Step 16
6Turn OFF the ignition. Probe both sides of the TAC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 22Go to Step 7
7Turn OFF the ignition. Disconnect the engine control module (ECM) connector containing the throttle actuator control (TAC) ignition 1 voltage circuit. Measure the resistance of the ignition 1 voltage circuit from the ECM electrical connector to the TAC fuse with a DMM. Refer to Troubleshooting with a Digital Multimeter . Does the resistance measure less than the specified value?3 ohmsGo to Step 8Go to Step 23
8Turn OFF the ignition. Inspect the throttle body for the following conditions. Refer to Diagnostic Aids: A throttle valve that is NOT in the rest position A throttle valve that is binding open or closed A throttle valve that is free to move open or closed WITHOUT spring pressure Did you find any of these conditions with the throttle body?Go to Step 24Go to Step 9
9IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Disconnect the throttle body harness connector. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 13Go to Step 10
10IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive.Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 14Go to Step 11
11Turn OFF the ignition. Connect the test lamp between the TAC motor control 1 and battery ground. IMPORTANT: Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then turn OFF?Go to Step 12Go to Step 15
12Turn OFF the ignition. Connect a test lamp between the TAC motor control 2 circuit and battery ground. IMPORTANT: Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then OFF?Go to Step 18Go to Step 15
13Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Does the test lamp illuminate?Go to Step 20Go to Step 19
14Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive. Does the test lamp illuminate?Go to Step 21Go to Step 19
15Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor controls circuits. Test the TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs . Did you find and correct the condition?Go to Step 26Go to Step 19
16Test the TAC ignition 1 voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 26Go to Step 17
17Test the motor control 1 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 26Go to Step 24
18Test for a poor connection or terminal tension at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 26Go to Step 24
19Test for a poor connection or terminal tension at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 26Go to Step 25
20Repair the short to voltage on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
21Repair the short to ground on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
22Repair the short to voltage on the TAC ignition 1 voltage circuit. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
23Repair the open or high resistance in the TAC ignition 1 voltage circuit. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
24Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 26
25Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?Go to Step 26
26Clear 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 2Go to Step 27
27Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK
IMPORTANT
The throttle angle and pedal angle may not correspond during this procedure.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool.
IMPORTANT
Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool.

DTC P1516

The numbers below refer to the step numbers on the diagnostic table.

  1. 8: The throttle valve is spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
  2. 11: When the ignition is turned ON, the ECM operates the throttle control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Are DTCs P0120, P0220, P2120, P2125, P2135, P2138 also set?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 3
3IMPORTANT: The throttle angle and pedal angle may not correspond during this procedure. Turn ON the ignition, with the engine OFF. Observe the throttle position (TP) sensor 1 and 2 angle parameters. Apply and release the accelerator pedal several times. Does the TP sensor 1 and 2 angle parameters increase as the pedal is applied and decrease as the pedal is released?Go to Step 4Go to Step 5
4Observe the Freeze Frame/Failure Records for this DTC. 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 5Go to Diagnostic Aids
5Turn ON the ignition, with the engine OFF. Probe both sides of the TAC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 6Go to Step 16
6Turn OFF the ignition. Probe both sides of the TAC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 22Go to Step 7
7Turn OFF the ignition. Disconnect the engine control module (ECM) connector containing the throttle actuator control (TAC) ignition 1 voltage circuit. Measure the resistance of the ignition 1 voltage circuit from the ECM electrical connector to the TAC fuse with a DMM. Refer to Troubleshooting with a Digital Multimeter . Does the resistance measure less than the specified value?3 ohmsGo to Step 8Go to Step 23
8Turn OFF the ignition. Inspect the throttle body for the following conditions. Refer to Diagnostic Aids: A throttle valve that is NOT in the rest position A throttle valve that is binding open or closed A throttle valve that is free to move open or closed WITHOUT spring pressure Did you find any of these conditions with the throttle body?Go to Step 24Go to Step 9
9IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Disconnect the throttle body harness connector. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 13Go to Step 10
10IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive.Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 14Go to Step 11
11Turn OFF the ignition. Connect the test lamp between the TAC motor control 1 and battery ground. IMPORTANT: Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then turn OFF?Go to Step 12Go to Step 15
12Turn OFF the ignition. Connect a test lamp between the TAC motor control 2 circuit and battery ground. IMPORTANT: Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then OFF?Go to Step 18Go to Step 15
13Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Does the test lamp illuminate?Go to Step 20Go to Step 19
14Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive. Does the test lamp illuminate?Go to Step 21Go to Step 19
15Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor controls circuits. Test the TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs . Did you find and correct the condition?Go to Step 26Go to Step 19
16Test the TAC ignition 1 voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 26Go to Step 17
17Test the motor control 1 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 26Go to Step 24
18Test for a poor connection or terminal tension at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 26Go to Step 24
19Test for a poor connection or terminal tension at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 26Go to Step 25
20Repair the short to voltage on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
21Repair the short to ground on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
22Repair the short to voltage on the TAC ignition 1 voltage circuit. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
23Repair the open or high resistance in the TAC ignition 1 voltage circuit. Refer to Wiring Repairs . Did you complete the repair?Go to Step 26
24Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 26
25Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?Go to Step 26
26Clear 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 2Go to Step 27
27Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK
IMPORTANT
The throttle angle and pedal angle may not correspond during this procedure.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool.
IMPORTANT
Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool.

DTC P2101

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: This step determines if the condition exists. A TP sensor DTC may cause this DTC to set.
  2. 3: Depending on the condition, DTC P1516, P2101, P2119, P2176 may set individually or together.
  3. 8: When the ignition is turned ON, the ECM operates the throttle actuator control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Turn ON the ignition, with the engine OFF. Clear the DTCs with a scan tool. Start the engine. Perform the following tests: Rapidly depress the accelerator pedal from the rest position to the wide open throttle (WOT) position and release pedal. Repeat the procedure several times. Slowly depress the accelerator pedal to WOT, then slowly return the pedal to closed throttle. Repeat the procedure several times. Observe the DTC information with a scan tool. Did DTC P0120, P0121, P0122, P0123, P0220, P0222, or P0223 fail this ignition?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 3
3Did DTC P1516, P2101, P2119, and/or P2176 fail this ignition?Go to Step 5Go to Step 4
4Observe the Freeze Frame/Failure Records for this DTC. 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 5Go to Diagnostic Aids
5Turn OFF the engine. Turn ON the ignition, with the engine OFF. Observe the throttle position (TP) sensor 1 voltage parameter with a scan tool. Is the voltage within the specified range?3.4-4 VGo to Step 6Go to DTC P0121
6Observe the TP sensor 2 voltage parameter with a scan tool. Is the voltage within the specified range?1.1-1.5 VGo to Step 7Go to DTC P0121
7NOTE: DO NOT use any mechanical device such as pliers or screwdrivers to disengage the connector. In order to prevent damage to the connector or harness wiring, both of the latches on the connector must be depressed with finger pressure only. When the latches are depressed the connector must then be pulled straight back without pulling on the wires in order to disengage. Failure to follow this procedure can lead to connector or wiring harness damage and failure. IMPORTANT: Disconnecting the throttle body harness connector causes additional DTCs to set. Disconnect the throttle body harness connector. Refer to Throttle Body Assembly Replacement . Turn ON the ignition, with the engine OFF. Measure the voltage of the throttle actuator control (TAC) motor control 1 and TAC motor control 2 circuits of the throttle actuator control motor with a DMM connected to the engine control module (ECM) housing. Is the voltage less than the specified value for both circuits?1 VGo to Step 8Go to Step 9
8Turn OFF the ignition. Connect the J 34730-405 Injector Test Lamp between the TAC motor control 1 and TAC motor control 2 circuit of the throttle body harness connector. See Special Tools . IMPORTANT: The test lamp intensity should be bright. Compare to another vehicle. Turn ON the ignition for about 5 seconds and then turn OFF the ignition while you observe the test lamp. Repeat this procedure, as necessary. Does the test lamp turn ON and then OFF each time the ignition is cycled?Go to Step 12Go to Step 11
9Is the voltage more than the specified value?1 VGo to Step 14Go to Step 10
10Test the TAC motor control circuit that measured below the specified value for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 18Go to Step 13
11Turn OFF the ignition. Disconnect the ECM. Test for continuity between the TAC motor control 1 and TAC motor control 2 circuit of the throttle body harness connector. Is there continuity?Go to Step 15Go to Step 13
12Test for shorted terminals and for poor connections at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 18Go to Step 16
13Test for shorted terminals and for poor connections at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 18Go to Step 17
14Repair the appropriate TAC motor control circuit for a short to voltage. Refer to Wiring Repairs . Did you complete the repair?Go to Step 18
15Repair the short between the TAC motor control circuits 1 and 2. Refer to Wiring Repairs . Did you complete the repair?Go to Step 18
16Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 18
17Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?Go to Step 18
18Clear 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 2Go to Step 19
19Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK
NOTE
DO NOT use any mechanical device such as pliers or screwdrivers to disengage the connector. In order to prevent damage to the connector or harness wiring, both of the latches on the connector must be depressed with finger pressure only. When the latches are depressed the connector must then be pulled straight back without pulling on the wires in order to disengage. Failure to follow this procedure can lead to connector or wiring harness damage and failure.
IMPORTANT
Disconnecting the throttle body harness connector causes additional DTCs to set.
IMPORTANT
The test lamp intensity should be bright. Compare to another vehicle.

P2119 Throttle Closed Position Performance

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests the internal circuits of the APP sensor 1 throughout its range of motion. If this DTC sets when slowly moving the pedal from the rest position to wide open throttle (WOT), replace the APP assembly for an internal fault.
  2. 5: The ECM produces a measurable steady-state amperage that provides the 5-volt reference to the APP sensor 1. If the amperage on the 5-volt reference circuit is less than 80 mA, there is a condition with the 5-volt reference circuit or the ECM.
  3. 7: This step tests for high resistance in the low reference circuit of the APP sensor 1. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition, with the engine OFF. Observe the accelerator pedal position (APP) sensor 1 voltage parameter with a scan tool. Is the voltage less than the specified value?0.3 VGo to Step 5Go to Step 3
3Observe the DTC information with a scan tool. Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position. Repeat this action several times. Did the DTC fail this ignition?Go to Step 13Go to Step 4
4Observe the Freeze Frame/Failure Records for this DTC. 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 5Go to Diagnostic Aids
5Turn OFF the ignition. Disconnect the APP sensor harness connector. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Turn ON the ignition, with the engine OFF. Set up a DMM to test amperage on the 400 mA scale. Measure the amperage from the 5-volt reference circuit of APP sensor 1 to the low reference circuit of APP sensor 1, with a DMM. Is the amperage more than the specified value?80 mAGo to Step 6Go to Step 9
6Turn OFF the ignition. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the APP sensor 1 and the signal circuit of the APP sensor 1. Turn ON the ignition, with the engine OFF. Observe the APP sensor 1 voltage parameter with a scan tool. Is the voltage within the specified range?4.8-5.2 VGo to Step 7Go to Step 10
7Turn OFF the ignition. Remove the engine control module (ECM)/transmission control module (TCM) fuse from the underhood fuse block. NOTE: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw. Measure the resistance from the low reference circuit of the APP sensor 1 to a good ground, with a DMM. Is the resistance less than the specified value?10 ohmsGo to Step 11Go to Step 8
8Disconnect the ECM. Test the low reference circuit of the APP sensor 1 for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
9IMPORTANT: The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors. Test the 5-volt reference circuit of the APP sensor 1 for the following conditions: A short to ground High resistance An open circuit Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
10Test the signal circuit of the APP sensor 1 for the following conditions: A short to ground High resistance An open circuit Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
11Test for an intermittent and for a poor connection at the APP assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 13
12Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 14
13Replace the APP assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 15
14Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 15
15Clear 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 2Go to Step 16
16Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
NOTE
Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
IMPORTANT
The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors.

DTC P2122

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests the internal circuits of the APP sensor 1 throughout its range of motion. If this DTC sets when slowly moving the pedal from the rest position to wide open throttle (WOT), replace the APP assembly for an internal fault.
  2. 7: This step tests for high resistance in the low reference circuit of the APP sensor 1. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition, with the engine OFF. Observe the accelerator pedal position (APP) sensor 1 voltage parameter, with a scan tool. Is the voltage more than the specified value?4.7 VGo to Step 5Go to Step 3
3Observe the DTC information with a scan tool. Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position. Repeat this action several times. Did the DTC fail this ignition?Go to Step 13Go to Step 4
4Observe the Freeze Frame/Failure Records for this DTC. 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 5Go to Diagnostic Aids
5Turn OFF the ignition. Disconnect the APP sensor harness connector. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Turn ON the ignition, with the engine OFF. Observe the APP sensor 1 voltage with the scan tool. Is the voltage less than the specified value?0.1 VGo to Step 6Go to Step 10
6Measure the voltage from the 5-volt reference circuit of the APP sensor 1 to a good ground, with a DMM. Is the voltage more than the specified value?6 VGo to Step 9Go to Step 7
7Turn OFF the ignition. Remove the engine control module (ECM)/transmission control module (TCM) fuse from the underhood fuse block. NOTE: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw. Measure the resistance from the low reference circuit of APP sensor 1 to a good ground, with a DMM. Is the resistance less than the specified value?10 ohmsGo to Step 11Go to Step 8
8Turn OFF the ignition. Disconnect the ECM. IMPORTANT: A short to voltage on the low reference circuit may cause internal ECM damage and sensor damage. Test the low reference circuit of the APP sensor 1 for an open, for a short to voltage, or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
9IMPORTANT: The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors. Test the 5-volt reference circuit of the APP sensor 1 for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition?Go to Step 15Go to Step 12
10Test the signal circuit of the APP sensor 1 for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
11Test for shorted terminals and poor connections at the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 13
12Test for shorted terminals and poor connections at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 14
13Replace the accelerator pedal assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 15
14Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 15
15Clear 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 2Go to Step 16
16Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
NOTE
Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
IMPORTANT
A short to voltage on the low reference circuit may cause internal ECM damage and sensor damage.
IMPORTANT
The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors.

DTC P2123

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests the internal circuits of the APP sensor 2 throughout its range of motion. If this DTC sets when slowly moving the pedal from the rest position to wide open throttle (WOT), replace the APP assembly for an internal fault.
  2. 5: The ECM produces a measurable steady-state amperage that provides the 5-volt reference to the APP sensor 2. If the amperage on the 5-volt reference circuit is less than 50 mA, there is a condition with the 5-volt reference circuit or the ECM.
  3. 7: This step tests for high resistance in the low reference circuit of the APP sensor 2. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition, with the engine OFF. Observe the accelerator pedal position (APP) sensor 2 voltage with a scan tool. Is the voltage less than the specified value?0.3 VGo to Step 5Go to Step 3
3Observe the DTC information with a scan tool. Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position. Repeat this action several times. Did the DTC fail this ignition?Go to Step 13Go to Step 4
4Observe the Freeze Frame/Failure Records for this DTC. 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 5Go to Diagnostic Aids
5Turn OFF the ignition. Disconnect the APP sensor harness connector. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Turn ON the ignition, with the engine OFF. Set up a DMM to test amperage on the 400 mA scale. Measure the amperage from the 5-volt reference circuit of APP sensor 2 to the low reference circuit of APP sensor 2, with a DMM. Is the amperage more than the specified value?50 mAGo to Step 6Go to Step 9
6Turn OFF the ignition. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the APP sensor 2 and the signal circuit of the APP sensor 2. Turn ON the ignition, with the engine OFF. Observe the APP sensor 2 voltage, with a scan tool. Is the voltage within the specified value?4.8-5.2 VGo to Step 7Go to Step 10
7Turn OFF the ignition. Remove the engine control module (ECM)/transmission control module (TCM) fuse from the underhood fuse block. NOTE: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw. Measure the resistance from the low reference circuit of the APP sensor 2 to a good ground, with a DMM. Is the resistance less than the specified value?10 ohmsGo to Step 11Go to Step 8
8Disconnect the ECM. Test the low reference circuit of the APP sensor 2 for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
9IMPORTANT: The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors. Test the 5-volt reference circuit of the APP sensor 2 for the following conditions: A short to ground High resistance An open circuit Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
10Test the signal circuit of the APP sensor 2 for the following conditions: A short to ground High resistance An open circuit Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
11Test for an intermittent and for a poor connection at the APP assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 13
12Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 14
13Replace the APP assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 15
14Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 15
15Clear 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 2Go to Step 16
16Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
NOTE
Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
IMPORTANT
The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors.

DTC P2127

The numbers below refer to the step numbers on the diagnostic table.

  1. 8: The throttle valve is spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
  2. 11: When the ignition is turned ON, the ECM operates the throttle control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Turn ON the ignition, with the engine OFF. Clear the DTCs with a scan tool. Start the engine. Perform the following tests: Rapidly depress the accelerator pedal from the rest position to the wide open throttle (WOT) position and release the pedal. Repeat the procedure several times. Slowly depress the accelerator pedal to WOT, then slowly return the pedal to closed throttle. Repeat the procedure several times. Turn OFF the ignition. Turn ON the ignition, with the engine OFF. Observe the DTC information with a scan tool. Does DTC P0121, P0122, P0123, P0222, P0223, P0689, P0690, P2135, or P2138 fail this ignition?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 3
3IMPORTANT: The throttle angle and pedal angle may not correspond during this procedure. Turn ON the ignition, with the engine OFF. Observe the Throttle Position (TP) Sensor 1 and 2 Angle parameters. Apply and release the accelerator pedal several times. Does the TP Sensor 1 and 2 Angle parameters increase as the pedal is applied and decrease as the pedal is released?Go to Step 4Go to Step 5
4Observe the Freeze Frame/Failure Records for this DTC. 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 5Go to Diagnostic Aids
5Turn ON the ignition, with the engine OFF. Probe both sides of the TAC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 6Go to Step 16
6Turn OFF the ignition. Probe both sides of the TAC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 23Go to Step 7
7Turn OFF the ignition. Disconnect the engine control module (ECM) connector containing the TAC ignition 1 voltage circuit. Measure the resistance of the ignition 1 voltage circuit from the ECM electrical connector to the throttle actuator control (TAC) fuse with a DMM. Refer to Troubleshooting with a Digital Multimeter . Does the resistance measure less than the specified value?3 ohmsGo to Step 8Go to Step 24
8Turn OFF the ignition. Inspect the throttle body for the following conditions: Refer to Diagnostic Aids: A throttle valve that is NOT in the rest position A throttle valve that is binding open or closed A throttle valve that is free to move open or closed WITHOUT spring pressure Did you find any of these conditions with the throttle body?Go to Step 25Go to Step 9
9IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Connect the engine control module connector. Disconnect the throttle body harness connector. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 13Go to Step 10
10IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive.Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 14Go to Step 11
11Turn OFF the ignition. Connect the test lamp between the TAC motor control 1 and battery ground. IMPORTANT: Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then turn OFF?Go to Step 12Go to Step 15
12Turn OFF the ignition. Connect a test lamp between the TAC motor control 2 circuit and battery ground. IMPORTANT: Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then OFF?Go to Step 19Go to Step 15
13Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Does the test lamp illuminate?Go to Step 21Go to Step 20
14Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive. Does the test lamp illuminate?Go to Step 22Go to Step 20
15Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor controls circuits. Test TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs . Did you find and correct the condition?Go to Step 27Go to Step 20
16Test the TAC ignition 1 voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 27Go to Step 17
17Test the motor control 1 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 27Go to Step 25
18Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Test the TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs . Did you find and correct the condition?Go to Step 27Go to Step 19
19Test for a poor connection or terminal tension at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 27Go to Step 25
20Test for a poor connection or terminal tension at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 27Go to Step 26
21Repair the short to voltage on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs . Did you complete the repair?Go to Step 27
22Repair the short to ground on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs . Did you complete the repair?Go to Step 27
23Repair the short to voltage on the TAC ignition 1 voltage circuit. Refer to Wiring Repairs . Did you complete the repair?Go to Step 27
24Repair the open or high resistance in the TAC ignition 1 voltage circuit. Refer to Wiring Repairs . Did you complete the repair?Go to Step 27
25Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 27
26Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?Go to Step 27
27Clear 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 2Go to Step 28
28Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK
IMPORTANT
The throttle angle and pedal angle may not correspond during this procedure.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool.
IMPORTANT
Ensure that the ECM completely powers down. This can be verified by the loss of communication with the scan tool.

DTC P2176

System Description

The valve lifter oil manifold (VLOM) solenoid for cylinder #1 is connected to a fused ignition 1 voltage circuit supplied by the powertrain relay in the underhood fuse block. The ground or control circuit for the solenoid is connected to a low-side driver internal to the engine control module (ECM). Each low-side driver has its own fault detection circuit, which monitors the solenoid control circuit for an incorrect voltage level. If an incorrect voltage level, such as an open, high resistance, short to ground, or a short to battery positive voltage is detected, the low-side driver will turn OFF and the fault detection circuit will communicate the condition to the central processor internal to the ECM. This DTC will set when the ECM detects an incorrect voltage level on the ignition 1 voltage circuit to the solenoid, or the solenoid control circuit, after the ignition switch is turned ON. This DTC could also set if an incorrect voltage level is detected when the ignition switch is turned OFF before the ECM powers down.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests for a short to battery positive voltage on the ignition 1 voltage circuit or the solenoid control circuit.
  2. 4: This step tests for an open circuit to the ENG 1 fuse.
  3. 5: The question in this step is based on the testing that took place in step 4.
  4. 9: This step performs a functional test of the VLOM assembly.
  5. 25: This step tests cylinder #1 VLOM solenoid for a short to ground condition.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. 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 3Go to Intermittent Conditions
3Turn OFF the ignition. Probe both test points of the ENG 1 fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on either test point of the ENG 1 fuse?Go to Step 18Go to Step 4
4Turn ON the ignition, with the engine OFF. Probe both test points of the ENG 1 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on both test points of the fuse?Go to Step 6Go to Step 5
5Does the test lamp illuminate on one test point of the fuse?Go to Step 22Go to Powertrain Relay Diagnosis
6Turn ON the ignition, with the engine OFF. Connect the scan tool to the diagnostic link connector (DLC). Listen for a clicking sound coming from the valve lifter oil manifold (VLOM) assembly area. Command the solenoid for cylinder #1 ON and OFF several times with a scan tool. Does the solenoid click each time when commanded ON and OFF with the scan tool?Go to Intermittent ConditionsGo to Step 7
7Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 8
8Turn OFF the ignition. Connect the cable labeled Resistance from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect the leads of the DMM to the resistance test ports on the DOD tester. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked solenoid #1 on the DOD tester. Does the resistance measure within the specified value?11-18 ohmsGo to Step 9Go to Step 40
9Turn OFF the ignition. Connect the cable labeled Power from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Listen for a clicking sound coming from the VLOM assembly area on the engine. Command the solenoid for cylinder #1 ON and OFF several times using the DOD tester. Does the solenoid click each time when commanded ON and OFF with the DOD tester?Go to Step 10Go to Displacement on Demand (DOD) Valve Lifter Oil Manifold Diagnosis and Testing
10Turn ON the ignition, with the engine OFF. Probe the ignition 1 voltage circuit wire terminal at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 11Go to Step 14
11Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 26Go to Step 12
12Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 30Go to Step 13
13Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Command the solenoid for cylinder #1 ON with a scan tool. Does the test lamp illuminate?Go to Intermittent ConditionsGo to Step 16
14Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 15
15Turn OFF the ignition. Measure the resistance of the ignition 1 voltage circuit from the VLOM wire harness electrical connector to the underhood fuse block wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 32Go to Step 39
16Turn OFF the ignition. Disconnect the engine control module (ECM) electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connectors at the ECM electrical connector and the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 17
17Turn OFF the ignition. Measure the resistance of the solenoid control circuit for the cylinder #1 from the VLOM wire harness electrical connector to the ECM wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 33Go to Step 41
18Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 19
19Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 28Go to Step 20
20Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 21
21Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 34Go to Step 39
22Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 23
23Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 24
24Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 35Go to Step 25
25Turn OFF the ignition. Connect the cable labeled RESISTANCE from the DOD tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect one lead of the DMM to a resistance test port on the DOD tester. Connect the other DMM lead to a good ground on the engine. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked Solenoid #1 on the DOD tester. Does the DMM display OL?Go to Step 39Go to Step 40
26Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector, and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 27
27Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 36Go to Step 41
28Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 29
29Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #1 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 37Go to Step 41
30Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #1. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 31
31Turn OFF the ignition. Disconnect the solenoid control circuit wire terminal for cylinder #1 from the ECM wire harness electrical connector. Refer to Tyco/AMP Connectors (CM 42-Way) or Tyco/AMP Connectors (Sensor) or Tyco/AMP Connectors (025 Cap) in Wiring Systems. Connect the ECM wire harness electrical connector to the ECM. Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #1 at the ECM electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 38Go to Step 41
32Repair the high resistance or an open in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
33Repair the high resistance or an open in the solenoid control circuit for cylinder #1 between the ECM wire harness electrical connector and the VLOM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
34Repair the short to battery positive in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
35Repair the short to ground in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
36Repair the short to ground in the solenoid control circuit for cylinder #1 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
37Repair the short to battery positive voltage in the solenoid control circuit for cylinder #1 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
38Repair the short to ignition 1 voltage in the solenoid control circuit for cylinder #1 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
39Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Did you complete the replacement?Go to Step 42
40Replace the VLOM assembly. Refer to Valve Lifter Oil Manifold Replacement in Engine Mechanical. Did you complete the replacement?Go to Step 42
41Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 42
42Clear 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 2Go to Step 43
43Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P3401

The valve lifter oil manifold (VLOM) solenoid for cylinder #4 is connected to a fused ignition 1 voltage circuit supplied by the powertrain relay in the underhood fuse block. The ground or control circuit for the solenoid is connected to a low-side driver internal to the engine control module (ECM). Each low-side driver has its own fault detection circuit, which monitors the solenoid control circuit for an incorrect voltage level. If an incorrect voltage level, such as an open, high resistance, short to ground, or a short to battery positive voltage is detected, the low-side driver will turn OFF and the fault detection circuit will communicate the condition to the central processor internal to the ECM. This DTC will set when the ECM detects an incorrect voltage level on the ignition 1 voltage circuit to the solenoid, or the solenoid control circuit, after the ignition switch is turned ON. This DTC could also set if an incorrect voltage level is detected when the ignition switch is turned OFF before the ECM powers down.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests for a short to battery positive voltage on the ignition 1 voltage circuit or the solenoid control circuit.
  2. 4: This step tests for an open circuit to the ENG 1 fuse.
  3. 5: The question in this step is based on the testing that took place in step 4.
  4. 9: This step performs a functional test of the VLOM assembly.
  5. 25: This step tests cylinder #4 VLOM solenoid for a short to ground condition.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. 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 3Go to Intermittent Conditions
3Turn OFF the ignition. Probe both test points of the ENG 1 fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on either test point of the ENG 1 fuse?Go to Step 18Go to Step 4
4Turn ON the ignition, with the engine OFF. Probe both test points of the ENG 1 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on both test points of the fuse?Go to Step 6Go to Step 5
5Does the test lamp illuminate on one test point of the fuse?Go to Step 22Go to Powertrain Relay Diagnosis
6Turn ON the ignition, with the engine OFF. Connect the scan tool to the diagnostic link connector (DLC). Listen for a clicking sound coming from the valve lifter oil manifold (VLOM) assembly area. Command the solenoid for cylinder #4 ON and OFF several times with a scan tool. Does the solenoid click each time when commanded ON and OFF with the scan tool?Go to Intermittent ConditionsGo to Step 7
7Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 8
8Turn OFF the ignition. Connect the cable labeled Resistance from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect the leads of the DMM to the resistance test ports on the DOD tester. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked solenoid #2 on the DOD tester. Does the resistance measure within the specified value?11-18 ohmsGo to Step 9Go to Step 40
9Turn OFF the ignition. Connect the cable labeled Power from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Listen for a clicking sound coming from the VLOM assembly area on the engine. Command the solenoid for cylinder #4 ON and OFF several times using the DOD tester. Does the solenoid click each time when commanded ON and OFF with the DOD tester?Go to Step 10Go to Displacement on Demand (DOD) Valve Lifter Oil Manifold Diagnosis and Testing
10Turn ON the ignition, with the engine OFF. Probe the ignition 1 voltage circuit wire terminal at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 11Go to Step 14
11Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #4 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 26Go to Step 12
12Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #4 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 30Go to Step 13
13Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #4 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Command the solenoid for cylinder #4 ON with a scan tool. Does the test lamp illuminate?Go to Intermittent ConditionsGo to Step 16
14Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 15
15Turn OFF the ignition. Measure the resistance of the ignition 1 voltage circuit from the VLOM wire harness electrical connector to the underhood fuse block wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 32Go to Step 39
16Turn OFF the ignition. Disconnect the engine control module (ECM) electrical connector that contains the solenoid control circuit for cylinder #4. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connectors at the ECM electrical connector and the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 17
17Turn OFF the ignition. Measure the resistance of the solenoid control circuit for the cylinder #4 from the VLOM wire harness electrical connector to the ECM wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 33Go to Step 41
18Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 19
19Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #4 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 28Go to Step 20
20Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 21
21Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 34Go to Step 39
22Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 23
23Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 24
24Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 35Go to Step 25
25Turn OFF the ignition. Connect the cable labeled RESISTANCE from the DOD tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect one lead of the DMM to a resistance test port on the DOD tester. Connect the other DMM lead to a good ground on the engine. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked Solenoid #2 on the DOD tester. Does the DMM display OL?Go to Step 39Go to Step 40
26Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #4. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector, and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 27
27Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #4 at the VLOM wire harness electrical connector with a test lamp connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 36Go to Step 41
28Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #4. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 29
29Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #4 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 37Go to Step 41
30Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #4. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 31
31Turn OFF the ignition. Disconnect the solenoid control circuit wire terminal for cylinder #4 from the ECM wire harness electrical connector. Refer to Tyco/AMP Connectors (CM 42-Way) or Tyco/AMP Connectors (Sensor) or Tyco/AMP Connectors (025 Cap) in Wiring Systems. Connect the ECM wire harness electrical connector to the ECM. Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #4 at the ECM electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 38Go to Step 41
32Repair the high resistance or an open in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
33Repair the high resistance or an open in the solenoid control circuit for cylinder #4 between the ECM wire harness electrical connector and the VLOM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
34Repair the short to battery positive in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
35Repair the short to ground in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
36Repair the short to ground in the solenoid control circuit for cylinder #4 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
37Repair the short to battery positive voltage in the solenoid control circuit for cylinder #4 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
38Repair the short to ignition 1 voltage in the solenoid control circuit for cylinder #4 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
39Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Did you complete the replacement?Go to Step 42
40Replace the VLOM assembly. Refer to Valve Lifter Oil Manifold Replacement in Engine Mechanical. Did you complete the replacement?Go to Step 42
41Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 42
42Clear 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 2Go to Step 43
43Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P3425

The valve lifter oil manifold (VLOM) solenoid for cylinder #6 is connected to a fused ignition 1 voltage circuit supplied by the powertrain relay in the underhood fuse block. The ground or control circuit for the solenoid is connected to a low-side driver internal to the engine control module (ECM). Each low-side driver has its own fault detection circuit, which monitors the solenoid control circuit for an incorrect voltage level. If an incorrect voltage level, such as an open, high resistance, short to ground, or a short to battery positive voltage is detected, the low-side driver will turn OFF and the fault detection circuit will communicate the condition to the central processor internal to the ECM. This DTC will set when the ECM detects an incorrect voltage level on the ignition 1 voltage circuit to the solenoid, or the solenoid control circuit, after the ignition switch is turned ON. This DTC could also set if an incorrect voltage level is detected when the ignition switch is turned OFF before the ECM powers down.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests for a short to battery positive voltage on the ignition 1 voltage circuit or the solenoid control circuit.
  2. 4: This step tests for an open circuit to the ENG 1 fuse.
  3. 5: The question in this step is based on the testing that took place in step 4.
  4. 9: This step performs a functional test of the VLOM assembly.
  5. 25: This step tests cylinder #6 VLOM solenoid for a short to ground condition.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. 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 3Go to Intermittent Conditions
3Turn OFF the ignition. Probe both test points of the ENG 1 fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on either test point of the ENG 1 fuse?Go to Step 18Go to Step 4
4Turn ON the ignition, with the engine OFF. Probe both test points of the ENG 1 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on both test points of the fuse?Go to Step 6Go to Step 5
5Does the test lamp illuminate on one test point of the fuse?Go to Step 22Go to Powertrain Relay Diagnosis
6Turn ON the ignition, with the engine OFF. Connect the scan tool to the diagnostic link connector (DLC). Listen for a clicking sound coming from the valve lifter oil manifold (VLOM) assembly area. Command the solenoid for cylinder #6 ON and OFF several times with a scan tool. Does the solenoid click each time when commanded ON and OFF with the scan tool?Go to Intermittent ConditionsGo to Step 7
7Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 8
8Turn OFF the ignition. Connect the cable labeled Resistance from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect the leads of the DMM to the resistance test ports on the DOD tester. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked solenoid #3 on the DOD tester. Does the resistance measure within the specified value?11-18 ohmsGo to Step 9Go to Step 40
9Turn OFF the ignition. Connect the cable labeled Power from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Listen for a clicking sound coming from the VLOM assembly area on the engine. Command the solenoid for cylinder #6 ON and OFF several times using the DOD tester. Does the solenoid click each time when commanded ON and OFF with the DOD tester?Go to Step 10Go to Displacement on Demand (DOD) Valve Lifter Oil Manifold Diagnosis and Testing
10Turn ON the ignition, with the engine OFF. Probe the ignition 1 voltage circuit wire terminal at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 11Go to Step 14
11Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #6 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 26Go to Step 12
12Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #6 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 30Go to Step 13
13Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #6 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Command the solenoid for cylinder #6 ON with a scan tool. Does the test lamp illuminate?Go to Intermittent ConditionsGo to Step 16
14Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 15
15Turn OFF the ignition. Measure the resistance of the ignition 1 voltage circuit from the VLOM wire harness electrical connector to the underhood fuse block wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 32Go to Step 39
16Turn OFF the ignition. Disconnect the engine control module (ECM) electrical connector that contains the solenoid control circuit for cylinder #6. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connectors at the ECM electrical connector and the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 17
17Turn OFF the ignition. Measure the resistance of the solenoid control circuit for the cylinder #6 from the VLOM wire harness electrical connector to the ECM wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 33Go to Step 41
18Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 19
19Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #6 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 28Go to Step 20
20Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 21
21Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 34Go to Step 39
22Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 23
23Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 24
24Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 35Go to Step 25
25Turn OFF the ignition. Connect the cable labeled RESISTANCE from the DOD tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect one lead of the DMM to a resistance test port on the DOD tester. Connect the other DMM lead to a good ground on the engine. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked Solenoid #3 on the DOD tester. Does the DMM display OL?Go to Step 39Go to Step 40
26Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #6. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector, and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 27
27Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #6 at the VLOM wire harness electrical connector with a test lamp connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 36Go to Step 41
28Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #6. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 29
29Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #6 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 37Go to Step 41
30Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #6. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 31
31Turn OFF the ignition. Disconnect the solenoid control circuit wire terminal for cylinder #6 from the ECM wire harness electrical connector. Refer to Tyco/AMP Connectors (CM 42-Way) or Tyco/AMP Connectors (Sensor) or Tyco/AMP Connectors (025 Cap) in Wiring Systems. Connect the ECM wire harness electrical connector to the ECM. Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #6 at the ECM electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 38Go to Step 41
32Repair the high resistance or an open in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
33Repair the high resistance or an open in the solenoid control circuit for cylinder #6 between the ECM wire harness electrical connector and the VLOM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
34Repair the short to battery positive in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
35Repair the short to ground in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
36Repair the short to ground in the solenoid control circuit for cylinder #6 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
37Repair the short to battery positive voltage in the solenoid control circuit for cylinder #6 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
38Repair the short to ignition 1 voltage in the solenoid control circuit for cylinder #6 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
39Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Did you complete the replacement?Go to Step 42
40Replace the VLOM assembly. Refer to Valve Lifter Oil Manifold Replacement in Engine Mechanical. Did you complete the replacement?Go to Step 42
41Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 42
42Clear 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 2Go to Step 43
43Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P3441

The valve lifter oil manifold (VLOM) solenoid for cylinder #7 is connected to a fused ignition 1 voltage circuit supplied by the powertrain relay in the underhood fuse block. The ground or control circuit for the solenoid is connected to a low-side driver internal to the engine control module (ECM). Each low-side driver has its own fault detection circuit, which monitors the solenoid control circuit for an incorrect voltage level. If an incorrect voltage level, such as an open, high resistance, short to ground, or a short to battery positive voltage is detected, the low-side driver will turn OFF and the fault detection circuit will communicate the condition to the central processor internal to the ECM. This DTC will set when the ECM detects an incorrect voltage level on the ignition 1 voltage circuit to the solenoid, or the solenoid control circuit, after the ignition switch is turned ON. This DTC could also set if an incorrect voltage level is detected when the ignition switch is turned OFF before the ECM powers down.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: This step tests for a short to battery positive voltage on the ignition 1 voltage circuit or the solenoid control circuit.
  2. 4: This step tests for an open circuit to the ENG 1 fuse.
  3. 5: The question in this step is based on the testing that took place in step 4.
  4. 9: This step performs a functional test of the VLOM assembly.
  5. 25: This step tests cylinder #7 VLOM solenoid for a short to ground condition.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. 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 3Go to Intermittent Conditions
3Turn OFF the ignition. Probe both test points of the ENG 1 fuse in the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on either test point of the ENG 1 fuse?Go to Step 18Go to Step 4
4Turn ON the ignition, with the engine OFF. Probe both test points of the ENG 1 fuse with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems. Does the test lamp illuminate on both test points of the fuse?Go to Step 6Go to Step 5
5Does the test lamp illuminate on one test point of the fuse?Go to Step 22Go to Powertrain Relay Diagnosis
6Turn ON the ignition, with the engine OFF. Connect the scan tool to the diagnostic link connector (DLC). Listen for a clicking sound coming from the valve lifter oil manifold (VLOM) assembly area. Command the solenoid for cylinder #7 ON and OFF several times with a scan tool. Does the solenoid click each time when commanded ON and OFF with the scan tool?Go to Intermittent ConditionsGo to Step 7
7Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 8
8Turn OFF the ignition. Connect the cable labeled Resistance from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect the leads of the DMM to the resistance test ports on the DOD tester. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked solenoid #4 on the DOD tester. Does the resistance measure within the specified value?11-18 ohmsGo to Step 9Go to Step 40
9Turn OFF the ignition. Connect the cable labeled Power from the Displacement on Demand (DOD) tester to the electrical connector on the VLOM assembly. Listen for a clicking sound coming from the VLOM assembly area on the engine. Command the solenoid for cylinder #7 ON and OFF several times using the DOD tester. Does the solenoid click each time when commanded ON and OFF with the DOD tester?Go to Step 10Go to Displacement on Demand (DOD) Valve Lifter Oil Manifold Diagnosis and Testing
10Turn ON the ignition, with the engine OFF. Probe the ignition 1 voltage circuit wire terminal at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 11Go to Step 14
11Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #7 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 26Go to Step 12
12Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #7 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 30Go to Step 13
13Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #7 at the VLOM wire harness electrical connector with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Command the solenoid for cylinder #7 ON with a scan tool. Does the test lamp illuminate?Go to Intermittent ConditionsGo to Step 16
14Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 15
15Turn OFF the ignition. Measure the resistance of the ignition 1 voltage circuit from the VLOM wire harness electrical connector to the underhood fuse block wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 32Go to Step 39
16Turn OFF the ignition. Disconnect the engine control module (ECM) electrical connector that contains the solenoid control circuit for cylinder #7. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connectors at the ECM electrical connector and the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 17
17Turn OFF the ignition. Measure the resistance of the solenoid control circuit for the cylinder #7 from the VLOM wire harness electrical connector to the ECM wire harness electrical connector with a DMM. Refer to Troubleshooting with a Digital Multimeter and Probing Electrical Connectors in Wiring Systems. Does the resistance measure greater than the specified value?2ohmsGo to Step 33Go to Step 41
18Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 19
19Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #7 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 28Go to Step 20
20Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 21
21Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 34Go to Step 39
22Turn OFF the ignition. Disconnect the VLOM assembly electrical connector. Test for shorted terminals and poor connections at the VLOM electrical connector and the VLOM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 23
23Turn OFF the ignition. Disconnect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Disconnect the underhood fuse block electrical connector that contains the ignition 1 voltage circuit for the VLOM. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Test for shorted terminals and poor connections at the underhood fuse block electrical connector and the underhood fuse block wire harness electrical connector. Refer to Underhood Electrical Center or Junction Block Replacement and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 24
24Turn OFF the ignition. Disconnect the ignition 1 voltage circuit wire terminal for the VLOM from the underhood fuse block electrical connector. Refer to Delphi Connectors (Weather Pack) or Delphi Connectors (Push To Seat) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Micro .64) in Wiring Systems. Connect the electrical connector that contained the ignition 1 voltage circuit for the VLOM back to the underhood fuse block assembly. Connect the battery negative cable at the battery. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical. Probe the ignition 1 voltage circuit wire terminal at the underhood fuse block with a test lamp that is connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 35Go to Step 25
25Turn OFF the ignition. Connect the cable labeled RESISTANCE from the DOD tester to the electrical connector on the VLOM assembly. Connect both the positive and the negative power leads of the DOD tester to the respective battery terminals at the battery. Connect one lead of the DMM to a resistance test port on the DOD tester. Connect the other DMM lead to a good ground on the engine. Set the DMM to measure resistance. Refer to Troubleshooting with a Digital Multimeter in Wiring Systems. Zero the DMM display. Monitor the DMM display. Press and hold the switch pad marked Solenoid #4 on the DOD tester. Does the DMM display OL?Go to Step 39Go to Step 40
26Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #7. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector, and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 27
27Turn OFF the ignition. Probe the solenoid control circuit wire terminal for cylinder #7 at the VLOM wire harness electrical connector with a test lamp connected to battery positive voltage. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 36Go to Step 41
28Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #7. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 29
29Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #7 at the VLOM wire harness electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 37Go to Step 41
30Turn OFF the ignition. Disconnect the ECM electrical connector that contains the solenoid control circuit for cylinder #7. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Test for shorted terminals and poor connections at the ECM electrical connector and at the ECM wire harness electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 42Go to Step 31
31Turn OFF the ignition. Disconnect the solenoid control circuit wire terminal for cylinder #7 from the ECM wire harness electrical connector. Refer to Tyco/AMP Connectors (CM 42-Way) or Tyco/AMP Connectors (Sensor) or Tyco/AMP Connectors (025 Cap) in Wiring Systems. Connect the ECM wire harness electrical connector to the ECM. Turn ON the ignition, with the engine OFF. Probe the solenoid control circuit wire terminal for cylinder #7 at the ECM electrical connector with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 38Go to Step 41
32Repair the high resistance or an open in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
33Repair the high resistance or an open in the solenoid control circuit for cylinder #7 between the ECM wire harness electrical connector and the VLOM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
34Repair the short to battery positive in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
35Repair the short to ground in the ignition 1 voltage circuit between the VLOM wire harness electrical connector and the underhood fuse block wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
36Repair the short to ground in the solenoid control circuit for cylinder #7 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
37Repair the short to battery positive voltage in the solenoid control circuit for cylinder #7 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
38Repair the short to ignition 1 voltage in the solenoid control circuit for cylinder #7 between the VLOM wire harness electrical connector and the ECM wire harness electrical connector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 42
39Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems. Did you complete the replacement?Go to Step 42
40Replace the VLOM assembly. Refer to Valve Lifter Oil Manifold Replacement in Engine Mechanical. Did you complete the replacement?Go to Step 42
41Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 42
42Clear 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 2Go to Step 43
43Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P3449