Test Procedure

WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2008 Mercury Sable, 2008 Mercury Mountaineer, 2008 Mercury Milan, 2008 Mercury Mariner, and 2008 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

KM1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)

Are DTCs P0534, P0645, P1460, P1464 or P1469 present?

Yes	No
For KOEO and KOER DTCs P0645 or P1460, GO to KM2. For continuous memory DTCs P0645 or P1460, GO to KM10. For KOEO and KOER DTC P1464, GO to KM8. For continuous memory DTCs P0534 or P1469, GO to KM12.	For all others, GO toDIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .

KM2 KOEO AND KOER DTCS P1460 OR P0645: VERIFY THAT THE ACCS PID IS OFF

NOTE: Verify the A/C and the defrost are off during KOEO/KOER self-tests. If the vehicle is not equipped with A/C, the A/CCR circuit is not used and DTC P1460/P0645 can be ignored.

Key ON, engine running.
A/C and defroster OFF.
Access the PCM and monitor the ACCS PID.
Is the PID state OFF?

Yes	No
GO to KM3.	REFER to the CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS articles> and diagnose the air conditioning (A/C) is inoperative/does not operate correctly symptom.

KM3 CHECK THE VPWR VOLTAGE TO THE A/CC RELAY

Key in OFF position.
A/CC Relay connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) A/CC Relay Connector, Harness Side	( - )
VPWR	Ground

Is the voltage greater than 10 V?

Yes	No
GO to KM4.	REPAIR the open circuit. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. REPEAT the self-test.

KM4 CHECK THE A/CC RELAY

Key in OFF position.
Carry out the A/CC relay component test. Refer to the Wiring Diagrams Cell 149 Component Testing.
Does the A/CC relay pass the component test?

Yes	No
GO to KM5.	INSTALL a new A/CC relay. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. CLEAR the DTCs. REPEAT the self-test.

KM5 CHECK THE A/CCR (WAC) CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) A/CC Relay Connector, Harness Side	( - )
A/CCR	Ground

Is the voltage less than 1 V?

Yes	No
GO to KM6.	REPAIR the short circuit. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. REPEAT the self-test.

KM6 CHECK THE A/CCR (WAC) CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

( + ) A/CC Relay Connector, Harness Side	( - )
A/CCR	Ground

Is the resistance greater than 10K ohms?

Yes	No
GO to KM7.	REPAIR the short circuit. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. REPEAT the self-test.

KM7 CHECK THE A/CCR (WAC) CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) A/CC Relay Connector, Harness Side	( - ) PCM Connector, Harness Side
A/CCR	A/CCR

Is the resistance less than 5 ohms?

Yes	No
GO to KM14.	REPAIR the open circuit. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. REPEAT the self-test.

KM8 KOEO AND KOER DTC P1464: VERIFY THE A/C AND DEFROST ARE OFF DURING THE SELF-TEST

Verify the A/C and defrost are off during the self-test.
Are the A/C and defrost off during the self-test?

Yes	No
GO to KM9.	Turn the A/C and defrost off. REPEAT the self-test where DTC P1464 was retrieved.

KM9 CHECK THE ACCS PID

Key ON, engine OFF.
A/C and defroster OFF.
Access the PCM and monitor the ACCS PID.
Is the PID state ON?

Yes	No
The ACCS PID indicates the PCM is being requested to turn the A/C on. REFER to the CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS articles> and diagnose the air conditioning (A/C) is inoperative/does not operate correctly symptom.	The ACCS PID indicates that the ACCS input to the PCM is low. VERIFY the test step results. Turn off the A/C and defrost. REPEAT the self-test.

KM10 CONTINUOUS MEMORY DTCS P1460 OR P0645: CHECK THE A/CCR (WAC) CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

NOTE: If the vehicle is not equipped with A/C, the A/CCR circuit is not used and the P1460/P0645 can be ignored.

NOTE: The A/C clutch clicks on when a concern is present.

Key ON, engine OFF.
Check the A/CCR (WAC) circuit for short to ground while carrying out the following:
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module
- Lightly tap on the A/CC relay to simulate road shock
Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary. CLEAR the DTCs. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. REPEAT the self-test.	GO to KM11.

KM11 CHECK THE A/CCR (WAC) FOR AN OPEN OR SHORT CIRCUIT TO VOLTAGE

NOTE: The A/C clutch clicks off if a concern is present.

Key ON, engine OFF.
Enter output test mode. Refer toOUTPUT TEST MODE (OTM) .
Command the outputs ON.
Check the A/CCR (WAC) circuit for an open or short to voltage while carrying out the following:
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module
- Lightly tap on the A/CC relay to simulate road shock
Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary. CLEAR the DTCs. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. REPEAT the self-test.	Unable to duplicate or identify the concern at this time. refer to PINPOINT TEST Z .

KM12 CONTINUOUS MEMORY DTCS P0534 OR P1469: CHECK FOR CAUSES OF FAST A/CCS CYCLING

Check the following:
- A/C system pressure
- A/CCS cycle times
REFER to the CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS articles > and diagnose the air conditioning (A/C) is inoperative/does not operate correctly symptom.
Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary.	GO to KM13.

KM13 CHECK FOR INTERMITTENT OPEN IN THE A/CCS CIRCUIT

NOTE: The ACCS PID turns off and on quickly when a concern is present, indicating an intermittent open.

Key ON, engine OFF.
Access the PCM and monitor the ACCS PID.
Turn on the A/C switch.
Check the A/CCR (WAC) circuit for an open or short to voltage while carrying out the following:
- Wiggle, shake, and bend small sections of the wiring harness while working from the component to the module.
- Lightly tap on the pressure switch (PS) (to simulate road shock).
Inspect the A/CCS connector.
Is a concern present?

Yes	No
ISOLATE the concern and REPAIR as necessary. CLEAR the DTCs. START the engine. TURN on the A/C switch. WAIT for 15 seconds. TURN off the A/C switch. REPEAT the self-test.	Unable to duplicate or identify the concern at this time. refer to PINPOINT TEST Z .

KM14 CHECK FOR CORRECT PCM OPERATION

Disconnect all the PCM connectors.
Visually inspect for:
- pushed out pins
- corrosion
Connect all the PCM connectors and make sure they seat correctly.
Carry out the PCM self-test and verify the concern is still present.
Is the concern still present?

Yes	No
INSTALL a new PCM. REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.