Diagnostic Test

CHECK FOR RELATED DTCS
1. Turn the ignition on.
2. With the scan tool, read Electric Vehicle Control Unit (EVCU) DTCs.
  Are there any System Voltage, or Sensor Reference Voltage DTCs present?
  
  Yes
  - Refer to the DTC INDEX - 500E and perform the appropriate diagnostic procedure.
  No
  - Go To 2
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 3
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
CHECK THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the A/C Pressure Transducer harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (C18) A/C Pressure Sensor Signal circuit at the A/C Pressure Transducer harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (C18) A/C Pressure Sensor Signal circuit for a short to voltage.
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 4
CHECK THE (C918) A/C PRESSURE GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. 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.
2. Disconnect the EVCU C1 harness connector.
3. Measure the resistance of the (C918) A/C Pressure Ground circuit between the A/C Pressure Transducer harness connector and the EVCU C1 harness connector.
  Is the resistance below 1.0 Ohm?
  
  Yes
  - Go To 5
  No
  - Repair the (C18) Sensor Ground circuit for an open circuit or high resistance.
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
A/C PRESSURE TRANSDUCER
1. Replace the A/C Pressure Transducer in accordance with the Service Information. Refer to TRANSDUCER, A/C PRESSURE, REMOVAL .
2. Reconnect all previously disconnected connectors.
3. Turn the ignition on.
4. With the scan tool, erase EVCU DTCs.
5. Turn the ignition off. Remove the key from the Ignition Switch, close doors and allow the EVCU to shut down.
6. Turn the ignition on.
7. With the scan tool, read the EVCU DTCs.
  Does this DTC reset?
  
  Yes
  - Go To 6
  No
  - Test Complete
  - Perform the EVCU VERIFICATION TEST. Refer to STANDARD PROCEDURE .
ELECTRIC VEHICLE CONTROL MODULE (EVCU)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Pressure Transducer and the Electric Vehicle Control Module (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 .