Diagnostic Test

CHECK IF THE DTC IS ACTIVE
1. With the scan tool, read Electric Vehicle Control Unit (EVCU) DTCs.
  Is the status for this DTC Active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
CHECK THE (C21) A/C SHUTOFF VALVE CONTROL CIRCUIT
1. Turn the ignition off.
2. Disconnect the A/C Shutoff Valve harness connector.
3. Turn the ignition on.
4. With the scan tool, actuate the Refrigerant Shutoff Valve.
5. Using a 12-volt test light connected to ground, check the (C21) A/C Shutoff Valve Control circuit at the A/C Shutoff Valve harness connector.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Go To 3
CHECK THE (C21) A/C SHUTOFF VALVE CONTROL CIRCUIT FOR AN OPEN
1. With the scan tool, turn off the actuator for the Refrigerant Shutoff Valve.
2. Turn the ignition off. Remove the key from the Ignition Switch, close doors and allow the EVCU to shut down.
  NOTE:
  Allow up to two minutes for the EVCU to shut down. Opening the vehicle door will interrupt the shut down process.
3. Disconnect the EVCU C2 harness connector.
4. Measure the resistance of the (C21) A/C Shutoff Valve Control circuit between the A/C Shutoff Valve harness connector and the EVCU C2 harness connector.
  Is the resistance below 1.0 Ohm?
  
  Yes
  - Go To 6
  No
  - Repair the (C21) A/C Shutoff Valve Control circuit for an open circuit or high resistance.
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (Z910) GROUND CIRCUIT FOR AN OPEN
1. With the scan tool, turn off the actuator for the Refrigerant Shutoff Valve.
2. Turn the ignition off.
3. Using a 12-volt test light connected to 12 volts, check the (Z910) Ground Circuit at the A/C Shutoff Valve harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Repair the (C21) A/C Shutoff Valve Control circuit for an open circuit or high resistance.
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE A/C SHUTOFF VALVE
1. Replace the A/C Shutoff Valve in accordance with the Service Information. Refer to LINE, A/C LIQUID, REMOVAL .
2. Turn the ignition on.
3. With the scan tool, erase EVCU DTCs.
4. Cycle the ignition off and then on.
5. With the scan tool, read EVCU DTCs.
  Is the status for this DTC Active?
  
  Yes
  - Go To 6
  No
  - Test Complete
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
ELECTRIC VEHICLE CONTROL UNIT (EVCU)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Shutoff Valve and the Electric Vehicle Control Unit (EVCU).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace and program the Electric Vehicle Control Module (EVCU) in accordance with the Service Information. Refer to UNIT, ELECTRIC VEHICLE CONTROL (EVCU), REMOVAL .
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .