Diagnostic Test
- CHECK FOR SYSTEM VOLTAGE DTCS IN ALL MODULES 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 HIGH VOLTAGE POWER DOWN .
Repair any Low or High Voltage DTCs in HCP, BPCM, PCM, or IDCM before proceeding and recheck operation.
- With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
- For future reference, with the scan tool, run and save a Vehicle Scan Report and all related recorded data.
Are there any system voltage high or low DTCs present in any modules?
Yes
- Diagnose and repair the low voltage system or battery issue. Erase DTCs and retest.
- Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to HV VERIFICATION TEST .
No
- Go To 2
- READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR DTC TO RETURN
- With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
- For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Go To 3
No
- Perform the appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
- ISOLATE AND CHECK THE (H493), (H494), (H393) AND (H394) CONTACTOR DRIVER CIRCUITS FOR AN OPEN/HIGH RESISTANCE
- The ignition must be off when checking the continuity of a circuit.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- 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.
- Connect one lead of the DVOM to the circuit being tested at the component harness connector.
- Connect the other lead to the circuit being tested at the ECU harness connector and measure the resistance of the circuit.NOTE:
When probing a circuit at an Electronic Control Unit (ECU) harness connector, always use an appropriate back probing tool to prevent any possible damage to the ECU terminals.
Is the resistance below 3.0 Ohms?
Yes
- Go To 4
No
- Repair the circuit for an open or high resistance.
- Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to HV VERIFICATION TEST .
- CHECK THE BPCM POWER AND GROUND CIRCUITS
- Load test the Fused B+ and ground circuits at the BPCM.
Did the circuits pass a load test?
Yes
- If all powers and grounds are ok, replace the Primary and Secondary High Voltage Battery Packs in accordance with the Service Information. Refer to HIGH VOLTAGE BATTERY, REMOVAL AND INSTALLATION .
- Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to HV VERIFICATION TEST .
No
- Repair the faulty power or ground circuit. Erase DTCs and retest.
- Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to HV VERIFICATION TEST .
- Load test the Fused B+ and ground circuits at the BPCM.