Diagnostic Test
- READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR DTC TO RETURN 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 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 2
No
- Perform the appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
- CHECK BATTERY CHILLER VALVE LIN BUS CIRCUIT FOR A SHORT TO GROUND
- Turn the ignition off.
- Disconnect the EVCU harness connector.
- Check for continuity between ground and the (D557) Battery Chiller Valve LIN circuit at the Battery Chiller Shut-Off Valve harness connector.
Is there continuity between ground and the (D557) Battery Chiller Valve LIN circuit?
Yes
- Repair the (D557) Battery Chiller Valve LIN 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 3
- CHECK BATTERY CHILLER VALVE LIN BUS CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
- Check for continuity between the (D557) Battery Chiller Valve LIN circuit and all other circuits at the EVCU harness connector.
Is there continuity between the (D557) Battery Chiller Valve LIN circuit and any other circuit?
Yes
- Repair the (D557) Battery Chiller Valve LIN circuit for a short to another circuit.
- Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
No
- Go To 4
- Check for continuity between the (D557) Battery Chiller Valve LIN circuit and all other circuits at the EVCU harness connector.
- CHECK RELATED HARNESS CONNECTIONS
- 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.
- Perform a terminal drag test on each connector terminal to 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.
- Using the recorded 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 EVCU DTCs.
Did the DTC return?
Yes
- Replace 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
- Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
- Test complete.