Pinpoint Test O: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON

Climate Control System

Pinpoint Test O: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON

Refer to Wiring Diagram Set 54, Manual Climate Control System for schematic and connector information. Diagrams By Number

Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information. Diagrams By Number

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.

For vehicles equipped with navigation, when MAX A/C is selected on the touch screen, the Audio Control Module (ACM) 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 O : 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.

O1 CHECK THE VEHICLE ENGINE OPTION

- Check the vehicle engine type.

Is the vehicle equipped with the 3.5L Gasoline Turbocharged Direct Injection (GTDI) engine

Yes
GO to O4.

No
GO to O2.

O2 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 O9.

No
GO to O3.

O3 CHECK THE AIR CONDITIONING COMPRESSOR CYCLING SWITCH (ACCS) PCM PID WITH HVAC MODULE DISCONNECTED

- Ignition OFF.

- Disconnect: HVAC Module- Electronic Manual Temperature Control (EMTC) C2357.

- Disconnect: HVAC Module- Dual Automatic Temperature Control (DATC) C228A.

- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C228B.

- Ignition ON.

- 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
For vehicles equipped with navigation, GO to O6.

For vehicles not equipped with navigation, GO to O7.

No
GO to O9.

O4 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 O9.

No
GO to O5.

O5 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PCM PID WITH HVAC MODULE DISCONNECTED

- Ignition OFF.

- Disconnect: HVAC Module- Electronic Manual Temperature Control (EMTC) C2357.

- Disconnect: HVAC Module- Dual Automatic Temperature Control (DATC) C228A.

- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C228B.

- Ignition ON.

- 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
For vehicles equipped with navigation, GO to O6.

For vehicles not equipped with navigation, GO to O7.

No
GO to O9.

O6 CHECK THE AIR CONDITIONING SWITCH STATUS (CC_SW_AC) FCIM (Front Controls Interface Module) PID WITH THE A/C OFF

- 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
GO to O8.

No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.

O7 CHECK THE AUDIO AND HVAC CONTROLS

- Operate all the functions of the audio and HVAC controls.

Do all the functions of the audio and HVAC controls operate correctly?

Yes
GO to O8.

No
INSTALL a new FCIM (Front Controls Interface Module). TEST the system for normal operation.

O8 CHECK THE 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. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

O9 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.