Pinpoint Test A: Transmission Fluid Heater Coolant Control Valve

WARNING: This page is about a different variant/trim than selected.

Refer to Electronic Engine Controls - 2.7L for schematic and connector information.

Normal Operation and Fault Conditions

The PCM receives input from the TFT sensor and determines if the transmission fluid heater coolant control valve should be open or closed depending on TFT. The PCM provides a ground to energize the valve as required by transmission fluid conditions.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
TCM P2681:00	Engine Coolant Bypass Valve "A" Control Circuit/Open: No Sub Type Information	Sets in continuous memory in the PCM if an open is detected in the engine coolant bypass valve circuit.
TCM P2682:00	Engine Coolant Bypass Valve "A" Control Circuit Low: No Sub Type Information	Sets in continuous memory in the PCM if high resistance is found in the engine coolant bypass valve circuit.
TCM P2683:00	Engine Coolant Bypass Valve "A" Control Circuit High: No Sub Type Information	Sets in continuous memory in the PCM if a short to ground is detected in the engine coolant bypass valve circuit.

Possible Sources

Transmission fluid heater coolant control valve circuitry
Transmission fluid heater coolant control valve
PCM

A1 RETRIEVE AND RECORD ALL DTCS

Using the diagnostic scan tool, retrieve all DTCs.

Was DTC P2681, P2682 or P2683 set?

Yes

GO to A2

No	The issue may not be the Transmission Fluid Heater Coolant Control Valve electrical system. REFER to Symptom Chart -- Transmission Cooling .

A2 CHECK BJB (BATTERY JUNCTION BOX) FUSE 8 (10A)
- Ignition OFF.
- Remove BJB fuse 8 (10A).
- Check BJB fuse 8 (10A).
Is the resistance less than 5 ohms?

Yes GO to A4

No GO to A3

A3 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE POWER CIRCUIT FOR A SHORT TO GROUND

Disconnect Transmission Fluid Heater Coolant Control Valve C1702.

Inspect for damaged or pushed-out terminals.

Measure.

Positive Lead	Measurement / Action	Negative Lead
C1703-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to A5

No	REPAIR the circuit.

A4 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE POWER CIRCUIT FOR AN OPEN

Install the fuse.

Disconnect Transmission Fluid Heater Coolant Control Valve C1702.

Ignition ON.

Measure.

Positive Lead	Measurement / Action	Negative Lead
C1703-1	Courtesy of FORD MOTOR COMPANY	Ground

Is voltage greater than 10 volts?

Yes

GO to A6

No	REPAIR the circuit.

A5 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE CONTROL CIRCUIT FOR A SHORT TO GROUND

Disconnect PCM C1232B.

Measure.

Positive Lead	Measurement / Action	Negative Lead
C1703-2	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to A6

No	REPAIR the circuit.

A6 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE CONTROL CIRCUIT FOR AN OPEN

Disconnect PCM C1232B.

Measure.

Positive Lead	Measurement / Action	Negative Lead
C1703-2	Courtesy of FORD MOTOR COMPANY	C1551B-70

Is the resistance less than 5 ohms?

Yes

GO to A7

No	REPAIR the circuit.

A7 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE

NOTE: The resistance specification below is for a temperature range between -40 deg.C - 200 deg.C (-40 deg.F - 392 deg.F)

Measure.

Positive Lead	Measurement / Action	Negative Lead
C1703-1	Courtesy of FORD MOTOR COMPANY	C1703-2

Is the resistance between 15 - 25 ohms?

Yes	INSTALL a new PCM. REFER to: Powertrain Control Module (PCM) 2.7L EcoBoost . PERFORM the Transmission Strategy Download, REFER to: Transmission Strategy Download

No	INSTALL a new Transmission Fluid Heater Coolant Control Valve. REFER to: Transmission Fluid Heater Coolant Control Valve 2.7L EcoBoost