Pinpoint Test H : The A/C (Air Conditioning) Is Always On - A/C (Air Conditioning) Mode Always Commanded On
- H1 RECHECK THE PCM (POWERTRAIN CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Make sure the HVAC controls are powered off.
- Using a diagnostic scan tool, clear the PCM Diagnostic Trouble Codes (DTCs).
- Using a diagnostic scan tool, carry out the PCM KOEO self-test.
Does DTC P1464 return?
Yes GO to H2 No IGNORE the DTC and CONTINUE diagnosing other Diagnostic Trouble Codes (DTCs) or symptoms. GO to the DTC Chart: Powertrain Control Module (PCM) or Symptom Chart: Climate Control - Electronic Manual Temperature Control (EMTC) . - H2 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH FIELD COIL VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect BJB C1035B.
- Disconnect A/C compressor clutch field coil C100.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C100-1 Ground
Is any voltage present?
Yes REPAIR the circuit. No GO to H3 - H3 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect BJB C1035C.
- Measure:
Positive Lead Measurement / Action Negative Lead C1035C-5 Ground
Is the resistance greater than 10, 000 ohms?
Yes GO to H4 No REPAIR the circuit. - H4 COMPARE THE FCIM (FRONT CONTROLS INTERFACE MODULE) EVAPORATOR TEMPERATURE (EVAP_TEMP) PID (PARAMETER IDENTIFICATION) TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PID (PARAMETER IDENTIFICATION)
- Ignition OFF.
- Connect BJB C1035B.
- Connect BJB C1035C.
- Connect A/C compressor clutch field coil C100.
- Allow the vehicle exterior and interior to stabilize to ambient temperature.
- Ignition ON.
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- Monitor and record the PCM AAT PID.
- Using a diagnostic scan tool, view the FCIM Parameter Identifications (PIDs).
- Monitor and record the FCIM (EVAP_TEMP) PID.
Are the temperature values similar (typically within 18 deg. C (32. 4 deg. F)?
Yes GO to H5 No DIAGNOSE the evaporator temperature sensor. GO to Pinpoint Test L - H5 CHECK THE FCIM (FRONT CONTROLS INTERFACE MODULE) A/C (AIR CONDITIONING) SWITCH STATUS (CC_SW_AC) PID (PARAMETER IDENTIFICATION)
- Ignition ON.
- Using a diagnostic scan tool, view FCIM Parameter Identifications (PIDs).
- Monitor the CC_SW_AC PID.
- Select panel mode, press and release the A/C button (indicator off) on the HVAC controls.
Does the PID display Active when pressed and Inactive when released?
Yes GO to H6 No GO to H9 - H6 CHECK THE A/C (AIR CONDITIONING) PRESSURE SENSOR (ACP_PRESS) PARAMETER IDENTIFICATION (PID)
- Using a diagnostic scan tool, view the PCM Parameter Identification (PIDs).
- With a manifold gauge set connected, compare the pressure readings of the manifold gauge set and the PCM Parameter Identification (PID) ACP_PRESS.
Are the pressure values of the manifold gauge set and the ACP_PRESS PCM PID within +/- 103 kPa (15) psi?
Yes GO to H7 No DIAGNOSE the A/C pressure transducer. GO to Pinpoint Test A - H7 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) REQUEST SIGNAL (AC_REQ) PID (PARAMETER IDENTIFICATION) WITH THE A/C (AIR CONDITIONING) OFF
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- Monitor the AC_REQ PID.
- While in panel mode, release the A/C button (indicator off) on the HVAC controls.
Does the PID display No?
Yes GO to H10 No GO to H8 - H8 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) REQUEST SIGNAL (AC_REQ) PID (PARAMETER IDENTIFICATION) WITH FCIM (FRONT CONTROLS INTERFACE MODULE) DISCONNECTED
- Ignition OFF.
- Disconnect FCIM C2402A.
- Ignition ON.
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- Monitor the AC_REQ PID.
Does the PID display No?
Yes GO to H10 No GO to H9 - H9 CHECK FOR CORRECT FCIM (FRONT CONTROLS INTERFACE MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all FCIM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect all FCIM connectors. Make sure they seat and latch correctly.
- Connect all disconnected connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to FCIM GUIDED ROUTINE . No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues. - H10 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all PCM connectors.
- Repair:
- corrosion (replace connector or terminals - clean module pins)
- damaged or bent pins - replace terminals/pins
- pushed-out pins - replace pins as necessary
- Reconnect all PCM connectors. Make sure they seat and latch correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to PCM Guided Routine Testing . No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.