Pinpoint Test H : The A/C (Air Conditioning) Is Always On - A/C (Air Conditioning) Mode Always Commanded On
NOTE:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- H1 CHECK THE A/C (AIR CONDITIONING) 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 H2 No INSTALL a new A/C clutch relay. - H2 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 C100.
- Disconnect the A/C clutch relay.
- 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 COMPARE THE EVAPORATOR TEMPERATURE SENSOR TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PID (PARAMETER IDENTIFICATION)
- Ignition OFF.
- Allow the vehicle exterior and interior to stabilize to ambient temperature.
- Disconnect Evaporator Temperature Sensor C296.
- Measure:
Positive Lead Measurement / Action Negative Lead C296-1 (component side) C296-2 (component side)
- Compare the resistance values to the table below:
Ambient Temperature °F (°C) Resistance ohms -39.9°F (-40°C) 98, 625 - 103, 275 ohms -4.0°F (-20°C) 28, 640 - 29, 600 ohms 32.0°F (°C) 9695 - 9895 ohms 68.0°F (20°C) 3675 - 3810 ohms 77.0°F (25°C) 2950 - 3050 ohms 86.0°F (30°C) 2370 - 2565 ohms 103.9°F (40°C) 1565 - 1635 ohms
- Ignition ON.
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- Monitor the AAT PID.
Is the resistance within the specified values for the temperatures?
Yes GO to H4 No INSTALL a new evaporator temperature sensor. REFER to: Evaporator Temperature Sensor . - H4 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 FCIM controls.
Does the PID display Active when pressed and Inactive when released?
Yes GO to H5 No GO to H8 - H5 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 PCMPID within +/- 103 kPa (15 psi)?
Yes GO to H6 No GO to Pinpoint Test A - H6 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 FCIM controls.
Does the PID display No?
Yes GO to H9 No GO to H7 - H7 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 ON.
- Disconnect FCIM C2402A.
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- Monitor the AC_REQ PID.
Does the PID display No?
Yes GO to H9 No GO to H8 - H8 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.
- 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 TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, Refer to FCIM Guided Routine Testing . 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. - H9 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 Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) 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.