Pinpoint Test P: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON
Climate Control System
Pinpoint Test P: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON
Normal Operation
Under normal operation, when the A/C button is pressed, a message is sent from the Front Controls Interface Module (FCIM) over the Medium Speed Controller Area Network (MS-CAN) bus to the HVAC module. The HVAC module then sends an A/C request message over the MS-CAN (Medium Speed Controller Area Network) bus to the Instrument Cluster (IC), then from the IC (Instrument Cluster) through the High Speed Controller Area Network (HS-CAN) bus to the PCM.
When MAX A/C is selected on the touch screen, the Front Display Interface Module (FDIM) sends a message over the MS-CAN (Medium Speed Controller Area Network) bus to the HVAC module that MAX A/C has been selected.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM
- HVAC module
PINPOINT TEST P : THE AIR CONDITIONING (A/C) IS ALWAYS ON - A/C MODE ALWAYS COMMANDED ON
NOTE: Before carrying out the following test, diagnose any HVAC, PCM or IC (Instrument Cluster) DTCs.
P1 CHECK THE AIR CONDITIONING SWITCH STATUS (CC_SW_AC) FCIM (Front Controls Interface Module) PID WITH THE A/C OFF
- Start the engine.
- Enter the following diagnostic mode on the scan tool: CC_SW_AC FCIM (Front Controls Interface Module) PID.
- Select PANEL press the A/C button (indicator off) on the HVAC controls.
Does the CC_SW_AC FCIM (Front Controls Interface Module) PID read Inactive?
Yes
For 3.5L only, GO to P2.
For 3.5L Gasoline Turbocharged Direct Injection (GTDI) only, GO to P4.
No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.
P2 CHECK THE AIR CONDITIONING COMPRESSOR CYCLING SWITCH (ACCS) PCM PID WITH THE A/C OFF
- Enter the following diagnostic mode on the scan tool: ACCS PCM PID.
- Select PANEL press the A/C button (indicator off) on the HVAC controls.
Does the ACCS PCM PID read OFF?
Yes
GO to P7.
No
GO to P3.
P3 CHECK THE AIR CONDITIONING COMPRESSOR CYCLING SWITCH (ACCS) PCM PID WITH HVAC MODULE DISCONNECTED
- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C2356A.
- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C2356B.
- Enter the following diagnostic mode on the scan tool: ACCS PCM PID.
- Observe the ACCS PCM PID.
Does the ACCS PCM PID read OFF?
Yes
GO to P6.
No
GO to P7.
P4 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PCM PID WITH THE A/C OFF
- Enter the following diagnostic mode on the scan tool: AC_REQ PCM PID.
- Select PANEL press the A/C button (indicator off) on the HVAC controls.
Does the AC_REQ PCM PID read OFF?
Yes
GO to P7.
No
GO to P5.
P5 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PCM PID WITH HVAC MODULE DISCONNECTED
- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C2356A.
- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C2356B.
- Enter the following diagnostic mode on the scan tool: ACCS PCM PID.
- Observe the AC_REQ PCM PID.
Does the AC_REQ PCM PID read OFF?
Yes
GO to P6.
No
GO to P7.
P6 CHECK THE HVAC MODULE CONNECTION
- Inspect the module connectors for:
- corrosion.
- pushed-out terminals.
- damaged terminals.
- Connect and correctly seat all the HVAC module connectors.
- Clear the DTCs.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new HVAC module. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
P7 CHECK THE PCM CONNECTION
- Disconnect all the PCM connectors.
- Inspect the module connectors for:
- corrosion.
- pushed-out terminals.
- damaged terminals.
- Connect and correctly seat all the PCM connectors.
- Clear the DTCs.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.