Pinpoint Test G : TCC, LPC Solenoids

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

Refer to Transmission Controls for schematic and connector information.

Normal Operation and Fault Conditions

When the electrical connector or solenoid is disconnected, inspect the connector for terminal condition, corrosion and contamination and the connector seal for damage. Clean, repair or install new components as required. If the power circuit to the transmission solenoids fails open, then all solenoids are failed electrically off. Check for an open, short to ground or the transmission connector disconnected. The TCC is controlled by a directly proportional solenoid. Like the shift solenoids the TCC solenoid is controlled by a smart driver capable of detecting open, short to ground and short to power faults. In the event of an open circuit or short to power fault the TCC circuit is failed open. The TCC and LPC solenoids share a high side driver. Anytime power is removed the transmission defaults to MAX line pressure with open TCC. LPC is controlled by an inversely proportional solenoid (0 current = max pressure, max current = min line pressure). The LPC solenoid is controlled by a "smart driver" capable of detecting an open, short to ground or short to power faults.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM P0740:00	Torque Converter Clutch Solenoid Circuit/Open: No Sub Type Information	This DTC sets if the PCM detects an open in the TCC solenoid circuitry.
PCM P0743:00	Torque Converter Clutch Solenoid Circuit Electrical: No Sub Type Information	This DTC sets if the fault was not present long enough for the PCM to determine a more specific fault. If more specific DTCs such as P0740 or P2769 are set resolve them first.
PCM P0748:00	Pressure Control Solenoid "A" Electrical: No Sub Type Information	This DTC sets if the fault was not present long enough for the PCM to determine a more specific fault. If more specific DTCs such as P0960, P0962 or P0963 are set resolve them first.
PCM P0960:00	Pressure Control Solenoid "A" Control Circuit/Open: No Sub Type Information	This DTC sets if the PCM detects an open in the pressure control solenoid circuitry or in the pressure control solenoid.
PCM P0961:00	Pressure Control Solenoid "A" Control Circuit Range/Performance: No Sub Type Information	This DTC sets if the PCM detects a short to ground, a short to power or an open in the pressure control solenoid circuitry or a short or open in the pressure control solenoid.
PCM P0962:00	Pressure Control Solenoid "A" Control Circuit Low: No Sub Type Information	This DTC sets if the PCM detects a short to ground in the pressure control solenoid circuitry or a short in the pressure control solenoid.
PCM P0963:00	Pressure Control Solenoid "A" Control Circuit High: No Sub Type Information	This DTC sets if the PCM detects a short to power in the pressure control solenoid circuitry.
PCM P2760:00	Torque Converter Clutch Pressure Control Solenoid Intermittent: No Sub Type Information	This DTC sets if the fault was not present long enough for the PCM to determine more specific fault. If a more specific DTC is set resolve it first.
PCM P2769:00	Torque Converter Clutch Circuit Low: No Sub Type Information	This DTC sets if the PCM detects a short to ground in the TCC circuitry or a short in the TCC solenoid.
PCM P2770:00	Torque Converter Clutch Circuit High: No Sub Type Information	This DTC sets if the PCM detects a short to ground in the TCC circuitry or an open or short to voltage in the TCC solenoid circuitry.

Possible Sources

Circuit open or shorted
Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
TCC or LPC solenoid
Transmission internal wiring harness
PCM

G1 CHECK THE TRANSMISSION SOLENOID POWER CONTROL 2 (TSPC2) CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect Transmission vehicle harness C168A.

Disconnect PCM C1381E.

Inspect the connectors for damaged or pushed out terminals, corrosion, loose wires and missing or damaged seals.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1381E-91	Courtesy of FORD MOTOR COMPANY	C168A-11

Is the resistance less than 3 ohms?

Yes

GO to G2

No	REPAIR the transmission vehicle harness circuit for an open. CLEAR the DTC.

G2 CHECK THE TRANSMISSION SOLENOID POWER CONTROL 2 (TSPC2) CIRCUIT FOR A SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1381E-91	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to G3

No	REPAIR the transmission vehicle harness circuit short to ground.

G3 CHECK THE SOLENOID CONTROL CIRCUITS FOR AN OPEN

Measure the resistance of the suspect solenoid control circuit using the following chart:

Positive Lead	Measurement / Action	Negative Lead
LPC Solenoid C1381E-73	Courtesy of FORD MOTOR COMPANY	C168A-24
TCC Solenoid C1381E-66	Courtesy of FORD MOTOR COMPANY	C168A-25

Is the resistance less than 3 ohms on the suspect circuit?

Yes

GO to G4

No	REPAIR the transmission vehicle harness circuit for an open. CLEAR the DTC.

G4 CHECK THE SOLENOID CONTROL CIRCUITS FOR A SHORT TO GROUND

Measure the resistance of the suspect solenoid control circuit to ground using the following chart:

Positive Lead	Measurement / Action	Negative Lead
LPC Solenoid C1381E-73	Courtesy of FORD MOTOR COMPANY	Ground
TCC Solenoid C1381E-66	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms on the suspect circuit?

Yes

GO to G5

No	REPAIR the transmission vehicle harness circuit short to ground. CLEAR the DTC.

G5 CHECK THE TRANSMISSION INTERNAL WIRING HARNESS SOLENOID CIRCUITS FOR A SHORT TO GROUND

Drain the transmission fluid and remove the transmission fluid pan. REFER to: Transmission Fluid Pan, Gasket and Filter .

Disconnect LPC C1840.

Disconnect TCC C1841.

Connect Transmission Vehicle Harness C168A.

For the LPC solenoid, measure:

Positive Lead	Measurement / Action	Negative Lead
C1381E-73	Courtesy of FORD MOTOR COMPANY	Ground
C1381E-91	Courtesy of FORD MOTOR COMPANY	Ground

For the TCC solenoid, measure:

Positive Lead	Measurement / Action	Negative Lead
C1381E-66	Courtesy of FORD MOTOR COMPANY	Ground
C1381E-91	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms on the suspect circuits?

Yes

GO to G6

No	INSTALL a new transmission internal wiring harness (both pieces). REFER to: Transmission Internal Wiring Harness .

G6 CHECK THE TRANSMISSION INTERNAL WIRING HARNESS SOLENOID CIRCUITS FOR AN OPEN

For the LPC solenoid, measure:

Positive Lead	Measurement / Action	Negative Lead
C1381E-73	Courtesy of FORD MOTOR COMPANY	C1840-2
C1381E-91	Courtesy of FORD MOTOR COMPANY	C1840-1

For the TCC solenoid, measure:

Positive Lead	Measurement / Action	Negative Lead
C1381E-66	Courtesy of FORD MOTOR COMPANY	C1841-2
C1381E-91	Courtesy of FORD MOTOR COMPANY	C1841-1

Are the resistances less than 3 ohms on the suspect circuits?

Yes	INSTALL a new solenoid. REFER to: Shift Solenoids (SS) .

No	INSTALL a new transmission internal wiring harness (both pieces). REFER to: Transmission Internal Wiring Harness .