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Power Distribution - Electrical Diagnostics

Factory FSM · 3 topics
DIAGNOSTIC CODE INDEX
DTC                                                                            Description
P129C                                                INVERTER CONTROL CIRCUIT HIGH (TIPM)
P129E                                        INVERTER CONTROL CIRCUIT OVERCURRENT (TIPM)
POWER DISTRIBUTION - ELECTRICAL DIAGNOSTICS
P129C-INVERTER CONTROL CIRCUIT HIGH (TIPM)
⚡ Wiring diagram: Body Control Modules Circuit (1 of 2)

Additional wiring

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS article.

When monitored

With the ignition on. Battery voltage greater than 10 volts. Once the inverter switch has been turned on, the CCN sends a request to the TIPM to turn on the Inverter.

Set conditions

 Set Condition:
An open or shorted high condition has been detected in the Inverter Control output circuit by the TIPM. One Trip Fault. Three good trips to turn off the MIL.

Possible causes

  • (P805) INVERTER CONTROL OUTPUT CIRCUIT OPEN
  • (P805) INVERTER CONTROL OUTPUT CIRCUIT SHORTED TO VOLTAGE
  • INVERTER MODULE
  • TOTALLY INTEGRATED POWER MODULE (TIPM)
  • Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding.

Diagnostic test

1) ACTIVE DTC
Ignition on, engine not running.
With a scan tool, select View DTCs.
Is the DTC Active at this time?
Yes
Go To 2) (P805) INVERTER CONTROL OUTPUT CIRCUIT SHORTED TO VOLTAGE.
No
Refer to the INTERMITTENT CONDITION Diagnostic Procedure. 2) (P805) INVERTER CONTROL OUTPUT CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Inverter Module harness connector.
Disconnect the TIPM C7 harness connector.
Turn the ignition on.
Measure the voltage of the (P805) Inverter Control Output circuit at the Inverter Module harness connector.
Is voltage present?
Yes
Repair the short to voltage in the (P805) Inverter Control Output circuit.
No
Go To 3). 3) INVERTER MODULE
Turn the ignition off.
Reconnect the TIPM harness connector.
Using a test light connected to ground, probe the Inverter Enable Switch Signal circuit at the Inverter Module harness connector.
Using the scan tool, actuate the Inverter Enable control.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Does the test light illuminate brightly?
Yes
Replace the Inverter Module per Service Information. Perform POWERTRAIN VERIFICATION TEST .
No
Go To 4). 4) (P805) INVERTER CONTROL OUTPUT CIRCUIT OPEN
Turn the ignition off.
Disconnect the TIPM harness connector.
Disconnect the Inverter Module harness connector.
Measure the resistance of the (P805) Inverter Control Output circuit between the TIPM and Inverter Module harness connector.
Is the resistance below 5.0 ohms?
Yes
Replace the Totally Integrated Power Module per Service Information. Perform BODY VERIFICATION TEST - VER 1 .
No
Repair the open in the (P805) Inverter Control Output circuit.
P129E-INVERTER CONTROL CIRCUIT OVERCURRENT (TIPM)
⚡ Wiring diagram: Body Control Modules Circuit (1 of 2)

Additional wiring

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS article.

When monitored

With the ignition on. Battery voltage greater than 10.4 volts.

Set conditions

 Set Condition:
An overcurrent condition is detected in the Inverter Control Output circuit. One Trip Fault. Three good trips to turn off the MIL.

Possible causes

  • TERMINAL DAMAGE OR CORROSION
  • (P805) INVERTER CONTROL OUTPUT CIRCUIT SHORTED TO GROUND
  • INVERTER MODULE
  • TOTALLY INTEGRATED POWER MODULE (TIPM)
  • Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding.

Diagnostic test

1) ACTIVE DTC
Ignition on, engine not running.
NOTE: Low battery voltage can also cause excessive current draw, in very hot and very cold ambient temperatures. Make sure the battery can pass a load test before continuing.
With a scan tool, select View DTCs.
Look closely at the temperatures at which this DTC set.
Is the DTC Active at this time?
Yes
Go To 2).
No
Refer to the INTERMITTENT CONDITION Diagnostic Procedure. 2) (P805) INVERTER CONTROL OUTPUT CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the TIPM harness connector.
Disconnect the Inverter Module harness connector.
Inspect the wiring connections for corrosion and repair as necessary.
Measure the resistance between ground and the (P805) Inverter Control Output circuit at the Inverter Module harness connector.
Is the resistance below 5.0 ohms?
Yes
Go To 3).
No
Repair the short to ground in the (P805) Inverter Control Output circuit. 3) INVERTER MODULE
Turn the ignition off.
Reconnect the TIPM harness connector.
Using a test light connected to ground, probe the Inverter Enable Switch Signal circuit at the Inverter Module harness connector.
Using the scan tool, actuate the Inverter Enable control.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Does the test light illuminate brightly?
Yes
Replace the Inverter Module per Service Information. Perform POWERTRAIN VERIFICATION TEST .
No
Replace the Totally Integrated Power Module per Service Information. Perform BODY VERIFICATION TEST - VER 1 .