Test Procedure

WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, 2011 Ford Fusion, 2010 Mercury Milan, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

DL1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) P0116, P0119, P0128, P1285, P1288, P1289, P128A, P1290 OR P1299

Are any of the following DTCs present during PCM or transaxle control module (TCM) self-test: P0116, P0119, P0128, P1285, P1288, P1289, P128A, P1290 or P1299?

Yes	No
For continuous memory DTC P0116, GO to DL24. For continuous memory DTCs P0119, P1289, P128A and P1290, GO to DL15. For continuous memory DTC P0128, GO to DL22. For DTC P1285, GO to DL18. For DTC P1288, GO to DL2. For KOEO and KOER DTCs P1289 or P1290, GO to DL7 . For KOER and continuous memory DTC P1299, GO to DL21.	Unable to duplicate or identify the concern at this time. RETURN to SYMPTOM CHARTS , for further direction.

DL2 SELF-TEST DTC P1288: CHECK THE COOLING SYSTEM

WARNING: TO AVOID PERSONAL INJURY DO NOT UNSCREW THE COOLANT PRESSURE RELIEF CAP WHILE THE ENGINE IS OPERATING OR HOT. THE COOLING SYSTEM IS UNDER PRESSURE. STEAM AND HOT LIQUID CAN COME OUT FORCEFULLY WHEN THE CAP IS LOOSENED SLIGHTLY. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.

NOTE: The DTC indicates the temperature sensor is out of self-test range. The engine is not at normal operating temperature.

Check the vehicle coolant level.

Is the cooling system OK?

Yes	No
GO to DL3.	REFER to the ENGINE COOLING SYSTEM (HYBRID) , for cooling system diagnostics.

DL3 CHECK IF THE ENGINE STARTS

Attempt to start the engine.

Does the engine start and run normally?

Yes	No
GO to DL6.	GO to DL4.

DL4 CHECK THE RESISTANCE OF THE CHT SENSOR WITH THE ENGINE OFF

NOTE: Refer to the RESISTANCE REFERENCE CHART for the resistance specifications.

Ignition OFF.
CHT Sensor connector disconnected.
Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) CHT Sensor Connector, Component Side	(-) CHT Sensor Connector, Component Side
CHT - Pin 1	SIGRTN - Pin 2

Is the resistance within specification?

Yes	No
CONNECT the CHT sensor. GO to DL5.	INSTALL a new CHT sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID) Clear the PCM DTCs. REPEAT the self-test.

DL5 CHECK IF THE VEHICLE ENGINE STARTS NORMALLY

Attempt to start the engine.

Does the engine start?

Yes	No
GO to DL6.	GO to PINPOINT TEST A .

DL6 CHECK THE OPERATION OF THE CHT SENSOR

Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
Run the engine until it reaches normal operating temperature.
Carry out the PCM KOEO self-test.

Is DTC P1288 present?

Yes	No
GO to DL20.	The engine temperature was not stabilized. REPAIR any other DTCs as necessary.

DL7 DTCS P1289 OR P1290: ACCESS THE CHT PID AND CHECK THE VOLTAGE

Ignition ON, engine OFF.
Access the PCM and monitor the CHT (VOLT) PID.

Is the voltage less than 0.2 V?

Yes	No
GO to DL8.	GO to DL9.

DL7 DTCS P1289 OR P1290: ACCESS THE CHT PID AND CHECK THE VOLTAG

Ignition ON, engine OFF
Access the PCM and monitor the CHT (VOLT) PID.

is the voltage less than 0.2 V?

Yes	No
Go to DL8.	Go to DL9.

DL8 CHECK FOR A GROUNDED CIRCUIT

Ignition OFF.
CHT Sensor connector disconnected.
Access the PCM and monitor the CHT (VOLT) PID.

Is the voltage greater than 4.6 V?

Yes	No
INSTALL a new CHT sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID) Clear the PCM DTCs. REPEAT the self-test.	GO to DL14.

DL9 CHECK FOR A VREF SHORT

Ignition OFF.
CHT Sensor connector disconnected.

Connect a 5 amp fused jumper wire between the following:

CONNECTOR PINS REFERENCE CHART

Point A CHT Sensor Connector, Harness Side	Point B CHT Sensor Connector, Harness Side
CHT - Pin 1	SIGRTN - Pin 2

Ignition ON, engine OFF.
Access the PCM and monitor the CHT (VOLT) PID.

Is the voltage less than 0.2 V?

Yes	No
REMOVE the jumper. GO to DL11.	REMOVE the jumper. GO to DL10.

DL10 CHECK THE CHT CIRCUIT FOR A SHORT TO VOLTAGE

CHT Sensor connector disconnected.
Ignition ON, engine OFF.
Measure the voltage between:

VOLTAGE REFERENCE CHART

(+) CHT Sensor Connector, Harness Side	(-)
CHT - Pin 1	Ground

Is the voltage greater than 5.5 V?

Yes	No
REPAIR the circuit. CHECK the CHT sensor for damage. Clear the PCM DTCs. REPEAT the self-test. GO to DL11.	GO to DL11.

DL11 CHECK THE RESISTANCE OF THE CHT SENSOR WITH THE ENGINE OFF

NOTE: Refer to the RESISTANCE REFERENCE CHART for the resistance specifications.

Ignition OFF.
CHT Sensor connector disconnected.
Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) CHT Sensor Connector, Component Side	(-) CHT Sensor Connector, Component Side
CHT - Pin 1	SIGRTN - Pin 2

Is the resistance within specification?

Yes	No
GO to DL12.	INSTALL a new CHT sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID) Clear the PCM DTCs. REPEAT the self-test.

DL12 CHECK THE SIGNAL AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS

PCM connector disconnected.
Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) CHT Sensor Connector, Harness Side	(-) PCM Connector, Harness Side
CHT - Pin 1	CHT - Pin E15
SIGRTN - Pin 2	SIGRTN - Pin E64

Are the resistances less than 5 ohms?

Yes	No
GO to DL13.	REPAIR the circuit. Clear the PCM DTCs. REPEAT the self-test.

DL13 CHECK THE SENSOR SIGNAL FOR A SHORT TO VREF

Ignition OFF.
PCM connector disconnected.
Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
CHT - Pin E15	VREF - Pin E63

Is the resistance greater than 10K ohms?

Yes	No
GO to DL26.	REPAIR the circuit. Clear the PCM DTCs. REPEAT the self-test.

DL14 CHECK THE SENSOR SIGNAL FOR A SHORT TO GROUND

Ignition OFF.
PCM connector disconnected.

Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
CHT - Pin E15	SIGRTN - Pin E64

Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) PCM Connector, Harness Side	(-) Vehicle Battery
CHT - Pin E15	Negative terminal

Is the resistance greater than 10K ohms?

Yes	No
GO to DL26.	REPAIR the circuit. Clear the PCM DTCs. REPEAT the self-test.

DL15 DTCS P0119, P1289, P128A AND P1290: INTERMITTENT CHECK

Ignition ON, engine OFF.
Access the PCM and monitor the CHT (VOLT) PID.
While observing the PID, carry out the following:

tap on the sensor to simulate road shock
wiggle the sensor connector

Is there a large change in the voltage reading?

Yes	No
DISCONNECT and INSPECT the connector. If OK, INSTALL a new CHT sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID) Clear the PCM DTCs. REPEAT the self-test.	GO to DL16.

DL16 CHECK THE ELECTRONIC ENGINE CONTROL (EEC) WIRING HARNESS

Access the PCM and monitor the CHT (VOLT) PID.
While observing the PID, wiggle, shake, and bend small sections of the wiring harness working from the sensor to the PCM.

Is there a large change in the voltage reading?

Yes	No
ISOLATE the concern. REPAIR as necessary.	GO to DL17.

DL17 CHECK THE PCM AND VEHICLE HARNESS CONNECTORS

PCM connector disconnected.
CHT Sensor connector disconnected.

Are the connectors and terminals OK?

Yes	No
Unable to duplicate or identify the concern at this time. DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .	REPAIR as necessary.

DL18 SELF-TEST DTC P1285: EARLY WARNING OF ENGINE OVERHEAT CONDITION

NOTE: An engine overheat condition was sensed by the CHT sensor.

NOTE: If the electric cooling fan does not operate, return to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS for electric cooling fan DTC or SYMPTOM CHARTS , for symptom diagnosis.

Check the cooling system for:

correct coolant level.
internal or external coolant leaks.
blockage of the radiator.
cooling fan operation.

Is the cooling system OK?

Yes	No
For CHT sensor check. GO to DL19.	REFER to the ENGINE COOLING SYSTEM (HYBRID) , for cooling system diagnostics. REPAIR as necessary.

DL19 CHECK THE OPERATION OF THE CHT SENSOR

Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
Run the engine until it reaches normal operating temperature.
Carry out the PCM KOEO self-test.

Is DTC P1285 present?

Yes	No
GO to DL20.	An engine overheat temperature was not detected. REPAIR any other DTCs as necessary.

DL20 CHECK THE RESISTANCE OF THE CHT SENSOR

NOTE: Refer to the RESISTANCE REFERENCE CHART for the resistance specifications.

The vehicle must be at normal operating temperature.
Ignition OFF.
CHT Sensor connector disconnected.
Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) CHT Sensor Connector, Component Side	(-) CHT Sensor Connector, Component Side
CHT - Pin 1	SIGRTN - Pin 2

Is the resistance within specification?

Yes	No
GO to DL26.	INSTALL a new CHT sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID) Clear the PCM DTCs. REPEAT the self-test.

DL21 SELF-TEST DTC P1299: INDICATES AN ENGINE OVERHEAT CONDITION

Check the engine coolant level.

Is the engine coolant fill level correct?

Yes	No
REFER to the ENGINE COOLING SYSTEM (HYBRID) , to diagnose the engine overheat condition.	REFER to the ENGINE COOLING SYSTEM (HYBRID) , to diagnose the coolant loss condition.

DL22 SELF-TEST DTC P0128: CHECK THE ENGINE COOLANT LEVEL

NOTE: DTC P0128 indicates the engine coolant temperature has not achieved the required engine operation temperature level, since start-up within a specified amount of time.

Check the engine coolant level.

Is the engine coolant fill level correct?

Yes	No
GO to DL23.	REFER to the ENGINE COOLING SYSTEM (HYBRID) , to diagnose the coolant loss condition.

DL23 CHECK THE SENSOR OPERATION

Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
Run the engine until it reaches normal operating temperature.
Access the PCM and monitor the CHT (TEMP) PID.

Is the temperature greater than 77° C (170.6°F)?

Yes	No
Unable to duplicate or identify the concern at this time.	REFER to the ENGINE COOLING SYSTEM (HYBRID) , to diagnose why the engine does not reach operating temperature.

DL24 DTC P0116: CHECK THE RESISTANCE OF THE CHT SENSOR WITH THE ENGINE OFF

NOTE: Verify the engine temperature is at ambient room temperature before continuing with this test. A soak period of 6 hours may be required. Refer to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS , for information concerning DTC P0116.

NOTE: Refer to the RESISTANCE REFERENCE CHART for the resistance specifications.

Ignition OFF.
CHT Sensor connector disconnected.
Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) CHT Sensor Connector, Component Side	(-) CHT Sensor Connector, Component Side
CHT - Pin 1	SIGRTN - Pin 2

Is the resistance within specification?

Yes	No
CONNECT the CHT. GO to DL25.	INSTALL a new CHT sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID) Clear the PCM DTCs. REPEAT the self-test.

DL25 DTC P0116: CHECK THE RESISTANCE OF THE CHT SENSOR

NOTE: Verify the engine is at normal operating temperature before taking the CHT reading.

NOTE: Refer to the RESISTANCE REFERENCE CHART for the resistance specifications.

Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
Run the engine until the engine temperature stabilizes.
Ignition OFF.
CHT Sensor connector disconnected.
Measure the resistance between:

RESISTANCE REFERENCE CHART

(+) CHT Sensor Connector, Component Side	(-) CHT Sensor Connector, Component Side
CHT - Pin 1	SIGRTN - Pin 2

Is the resistance within specification?

Yes	No
Unable to duplicate or identify the concern at this time.	INSTALL a new CHT sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID) Clear the PCM DTCs. REPEAT the self-test.

DL26 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.
Verify the concern is still present.

Is the concern still present?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.