Pinpoint Test H : The A/C (Air Conditioning) Is Always On - A/C (Air Conditioning) Mode Always Commanded On
- Refer to MANUAL CLIMATE CONTROL SYSTEM
for schematic and connector information.
Normal Operation and Fault Conditions
Control System Logic REFER to: Climate Control System - Vehicles With: Electronic Automatic Temperature Control (EATC) - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition HVAC P1464:00 A/C Demand Out Of Self Test Range: No Sub Type Information This DTC sets when the PCM senses an A/C request when performing a self-test. Possible Sources
- Wiring, terminals or connectors
- PCM
- HVAC control module
- NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- H1 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 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(s) . - H2 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY
- Carry out the component test on the A/C clutch relay. Refer to OEM WIRING DIAGRAMS COMPONENT TESTING for schematic and connector information.
Did the relay pass the component test?
Yes GO to H3 No INSTALL a new A/C clutch relay. - H3 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.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C100-1 Ground
Is any voltage present?
Yes REPAIR the circuit. No GO to H4 - H4 COMPARE THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE (A/C) EVAPORATOR TEMPERATURE (EVAP_TEMP) PID (PARAMETER IDENTIFICATION) TO THE PCM (POWERTRAIN CONTROL MODULE) AMBIENT AIR TEMPERATURE (AAT) PID (PARAMETER IDENTIFICATION)
- Ignition OFF.
- 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 deg.C (32.4 deg.F)?
Yes GO to H5 No DIAGNOSE the evaporator temperature sensor. GO to Pinpoint Test L - H5 CHECK THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE (A/C) SWITCH STATUS (CC_SW_AC) PID (PARAMETER IDENTIFICATION) WITH THE A/C (AIR CONDITIONING) ON
- Ignition ON.
- Using a diagnostic scan tool, monitor the HVAC control module CC_SW_AC PID.
- Monitor the CC_SW_AC PID.
- On the HVAC controls, select PANEL and then press the A/C button (indicator ON).
Does the PID display Active or On when pressed and Inactive or Off 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 or OFF?
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 HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE DISCONNECTED
- Ignition OFF.
- Disconnect HVAC control module C2357A.
- Ignition ON.
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- Monitor the AC_REQ PID.
Does the PID display No or OFF?
Yes GO to H10 No GO to H9 - H9 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 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, INSTALL a new HVAC control module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module . 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. - H10 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all PCM 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 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 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.