Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnostic Test
- CHECK FOR AN ACTIVE DTC WARNING:
On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury.
Read the HIGH-VOLTAGE SAFETY PROCEDURES. Refer to HIGH VOLTAGE SAFETY PROCEDURES .
When the HIGH-VOLTAGE POWER-DOWN PROCEDURE is necessary. Refer to VEHICLE HIGH VOLTAGE POWER DOWN .
- With the scan tool, read DTCs and record on the repair order.
- Record the Environmental Data.
- With the scan tool, erase DTCs.
- Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read Integrated Dual Charge Module (IDCM) DTCs.
Did the DTC return?
Yes
- Go To Next Step.
No
- Perform the TESTING FOR AN INTERMITTENT CONDITION procedure Refer to TESTING FOR AN INTERMITTENT CONDITION .
- CHECK THE (H17) WAKE-UP SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Turn the Ignition off.
- Disconnect the IDCM C1 harness connector.
- Disconnect the EVCU harness connector.
- Check for continuity to ground on the (H17) Wake-Up Signal circuit.
Is continuity to ground present in the (H17) Wake-Up Signal circuit?
Yes
- Repair the (H17) Wake-Up Signal circuit for a short to ground.
- Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
No
- Go To Next Step.
- CHECK RELATED EVCU AND COMPONENT CONNECTIONS
- Perform any Service Bulletins that apply.
- Disconnect all EVCU harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- 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.
- Reconnect all EVCU harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Replace and program the Electric Vehicle Control Unit (EVCU) in accordance with the Service Information. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) .
- Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
No
- The wiring or poor connection problem has been repaired.
- Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.