Diagnostic Test

1. Check for any applicable Service Bulletins or Flash updates related to the DTC.

   Are there any applicable Service Bulletins or Flash updates?

   Yes 

   • Perform the applicable repair.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

   No 

   • Go To  2

1. With the scan tool, read and record DTCs in all Electronic Control Units (ECUs) on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.

Did the DTC return?

Yes 

• Go To  3

No 

• Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .

1. Refer to the recorded DTCs.

   Are there any system voltage or 5-Volt Reference DTCs active or pending?

   Yes 

   • Perform the applicable diagnostic procedure(s). Refer to 3.6L (GPEC 2A) - DIAGNOSTIC CODE INDEX .

   No 

   • Go To  4

1. Turn the ignition off.
2. Check the Throttle Body harness connector for proper connection at the Throttle Body.
3. Verify that the connector is completely plugged in and properly locked prior to disconnecting.
4. Disconnect the Throttle Body harness connector and check for any pushed out, damaged or spread terminals.

   Were any issues found with the connector or terminals?

   Yes 

   • Repair the damaged terminal or properly connect and lock the Throttle Body harness connector and retest for DTCs.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

   No 

   • Go To  5

1. Turn the ignition off.
2. Disconnect the harness connector at the component of the circuit being tested. Note:  Use the appropriate wiring diagram as a guide to follow the path of the circuit.
3. Turn the ignition on.
4. Using a DVOM, measure the voltage of the circuit being tested at the component harness connector.

Is the voltage above 5.2 volts?

Yes 

• Go To  6

No 

• Repair the (F855) 5-Volt Supply circuit for an open or short to ground.
• Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the Powertrain Control Module (PCM) and every component harness connector containing the circuit being tested. Note:  Use the appropriate wiring diagram as a guide to follow the path of the circuit.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.

1. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
   NOTE:

   There should be no continuity between ground and the circuit being tested.

   Is there continuity between ground and the circuit being tested?

   Yes 

   • Repair the circuit for a short to ground. Use the appropriate wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

   No 

   • Go To  7

1. The ignition must be off when checking for a short between circuits.
2. Isolate the circuit by disconnecting the Powertrain Control Module (PCM) and every component harness connector containing the circuit being tested. Note:  Use the appropriate wiring diagram as a guide to follow the path of the circuit.
3. Connect the test leads of the DVOM and check for continuity between the circuits being tested at the component harness connector.

1. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
   NOTE:

   There should be no continuity between the circuits being tested.

   Is there continuity between the circuits?

   Yes 

   • Repair the short between the circuits.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

   No 

   • Go To  8

1. The ignition must be off when checking the continuity of a circuit.
2. Isolate the circuit by disconnecting the Powertrain Control Module (PCM) and the component harness connector containing the circuit being tested. Note:  Use the appropriate wiring diagram as a guide to follow the path of the circuit.
3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
5. Connect the other lead to the circuit being tested at the GPEC Adaptor and measure the resistance of the circuit.

1. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.

   Is the resistance below 3.0 Ohms?

   Yes 

   • Go To  9

   No 

   • Repair the circuit for an open or high resistance.
   • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

1. The Powertrain Control Module (PCM) harness connectors must be connected to the PCM during this test step.
2. Disconnect the sensor harness connector.
3. With the ignition in the off position, connect a fused jumper between the sensor signal circuit and the 5-Volt Supply circuit at the sensor harness connector.
4. Turn the ignition on.
5. With the scan tool, read DTCs.

Does the scan tool display the SENSOR SIGNAL CIRCUIT HIGH DTC with the jumper in place?

Yes 

• Replace the faulty sensor in accordance with the Service Information. Refer to THROTTLE BODY, REMOVAL AND INSTALLATION .
• Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

No 

• Go To  10

1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
   • Proper connector installation.
   • Damaged connector locks.
   • Corrosion.
   • Other signs of water intrusion.
   • Weather seal damage (if equipped).
   • Bent terminals.
   • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
   • Terminals that have been pushed back into the connector cavity.
   • Check for spread terminals and verify proper terminal tension.

   Repair any conditions that are found.

6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.

    Did the DTC return?

    Yes 

    • Replace the Powertrain Control Module in accordance with the Service information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
    • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

    No 

    • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
    • Test complete.