Pinpoint Test M: The Air Conditioning (A/C) Is Always On - A/C Mode Always Commanded On
Climate Control System
Pinpoint Tests
Pinpoint Test M: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON
Refer to Wiring Diagram Set 54 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), Manual Climate Control System for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 55 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), Automatic Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, when A/C is requested the HVAC module then sends an A/C request message over the Medium Speed Controller Area Network (MS-CAN) bus to the Instrument Cluster (IC), then from the IC through the High Speed Controller Area Network (HS-CAN) bus to the PCM.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM
- HVAC module
PINPOINT TEST M: 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 DTCs.
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M1 CHECK THE AIR CONDITIONING COMPRESSOR CYCLING SWITCH (ACCS) PCM PID WITH THE A/C OFF
- Start the engine.
- Enter the following diagnostic mode on the scan tool: ACCS PCM PID.
- Select PANEL mode on the HVAC module and make sure the A/C button and indicator are OFF.
- Does the ACCS PCM PID read OFF?
Yes
GO to M4.
No
Electronic Manual Temperature Control (EMTC) systems, GO to M3.
Dual Automatic Temperature Control (DATC) systems, GO to M2.
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M2 CHECK THE AIR CONDITIONING SWITCH STATUS (AC_SEL_SW) HVAC PID WITH THE A/C OFF
- Enter the following diagnostic mode on the scan tool: AC_SEL_SW HVAC PID.
- Select PANEL mode on the HVAC module and make sure the A/C button and indicator are OFF.
- Does the AC_SEL_SW HVAC PID read not pressed?
Yes
GO to M4.
No
GO to M3.
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M3 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. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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M4 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.
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