Pinpoint Test L : The A/C (Air Conditioning) Is Always On - A/C (Air Conditioning) Mode Always Commanded On
- L1 RECHECK THE PCM (POWERTRAIN CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Make sure the HVAC control module is 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 L2 No IGNORE the DTC and CONTINUE diagnosing other Diagnostic Trouble Codes (DTCs) or symptoms. GO to DTC Chart: PCM or SYMPTOM CHART - Climate Control Systems . - L2 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY
- Disconnect the A/C clutch relay.
- Carry out the component test on the A/C clutch relay. Refer to Component Testing for schematic and connector information.
Did the relay pass the component test?
Yes GO to L3 No INSTALL a new A/C clutch relay. - L3 CHECK THE A/C (AIR CONDITIONING) COMPRESSOR CLUTCH FIELD COIL VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect A/C compressor clutch field coil C1680 .
- Ignition ON.
- For 2.5L, measure:
Positive Lead Measurement / Action Negative Lead C1680-1 Ground
Is any voltage present?
Yes REPAIR the circuit. No GO to L4 - L4 COMPARE THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE EVAPORATOR TEMPERATURE (EVAP_TEMP) PID (PARAMETER IDENTIFICATION) TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PID (PARAMETER IDENTIFICATION)
- Ignition OFF.
- Connect the A/C clutch relay.
- Allow the vehicle exterior and interior to stabilize to the outside ambient temperature.
- Ignition ON.
- Using a diagnostic scan tool, view the PCM Parameter Identification (PIDs).
- Monitor and record the PCM PID AAT.
- Using a diagnostic scan tool, view the HVAC control module Parameter Identification (PIDs).
- Monitor and record the HVAC control module PID EVAP_TEMP.
Are the temperature values similar (typically within 18 °C (32.4 °F))?
Yes GO to L5 No GO to Pinpoint Test E - L5 CHECK THE A/C (AIR CONDITIONING) PRESSURE SENSOR (ACP_PRESS) PARAMETER IDENTIFICATION (PID)
- Ignition ON.
- 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 L6 No GO to Pinpoint Test B - L6 CHECK THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE A/C (AIR CONDITIONING) SWITCH STATUS (CC_SW_AC) PID (PARAMETER IDENTIFICATION) WITH THE A/C (AIR CONDITIONING) OFF
- Ignition ON.
- Using a diagnostic scan tool, monitor the HVAC control module CC_SW_AC PID.
- Using the HVAC controls, select PANEL then press and release the A/C button (indicator off).
Does the PID display On when the A/C button is pressed and Off when released?
Yes GO to L7 No GO to L9 - L7 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, monitor the PCM AC_REQ PID.
- Using the HVAC controls, deactivate the A/C.
Does the PID display OFF?
Yes GO to L9 No GO to L8 - L8 CHECK THE PCM (POWERTRAIN CONTROL MODULE) A/C (AIR CONDITIONING) REQUEST SIGNAL (AC_REQ) PID (PARAMETER IDENTIFICATION) WITH THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE DISCONNECTED
- Ignition OFF.
- Disconnect HVAC control module C228A .
- Ignition ON.
- Using a diagnostic scan tool, monitor the PCM AC_REQ PID.
Does the PID display OFF?
Yes GO to L9 No GO to L10 - L9 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION
- Ignition OFF.
- Disconnect and inspect all HVAC control module electrical connectors (if not previously disconnected).
- Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- Connect all HVAC control module electrical 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 Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new HVAC control module. Refer to: Climate Control Assembly . 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. - L10 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all PCM electrical connectors (if not previously disconnected).
- Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- Connect all PCM electrical 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 Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, 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.