Pinpoint Test G: TCC, LPC Solenoids
- Refer to Wiring Diagrams TRANSMISSION CONTROLS - 10R80
for schematic and connector information.
Normal Operation and Fault Conditions
The TCC is controlled by a directly proportional solenoid. Transmission line pressure is controlled by an inversely proportional solenoid meaning no current provides maximum line pressure, and maximum current provides minimum line pressure. The TCC and LPC solenoids are controlled by smart drivers capable of detecting open, short to ground or short to power faults. In the event of an open circuit or short to power fault, the TCC fails open, and the LPC solenoid fails to maximum line pressure. The TCC and LPC solenoids share a high side driver. Anytime power is removed the transmission defaults to MAX line pressure with the TCC released.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM P0740:00 Torque Converter Clutch Solenoid Circuit/Open: No Sub Type Information This DTC indicates an open circuit in the TCC solenoid circuit. PCM P0743:00 Torque Converter Clutch Solenoid Circuit Electrical: No Sub Type Information This DTC illuminates the wrench light in conjunction with P0740, P2769 and/or P2770. Resolve the more specific DTC first. PCM P0748:00 Pressure Control Solenoid "A" Electrical: No Sub Type Information This DTC illuminates the wrench light in conjunction with P0960, P0962 and/or P0963. Resolve the more specific DTC first. PCM P0960:00 Pressure Control Solenoid "A" Control Circuit/Open: No Sub Type Information This DTC indicates an open circuit in the LPC solenoid circuit. PCM P0961:00 Pressure Control Solenoid "A" Control Circuit Range/Performance: No Sub Type Information This DTC indicates an LPC solenoid fault, but the fault did not last long enough to set a more specific DTC. PCM P0962:00 Pressure Control Solenoid "A" Control Circuit Low: No Sub Type Information This DTC indicates a short to ground in the LPC solenoid circuit. PCM P0963:00 Pressure Control Solenoid "A" Control Circuit High: No Sub Type Information This DTC indicates a short to power in the LPC solenoid circuit. PCM P2669:00 Actuator Supply Voltage "B" Circuit/Open: No Sub Type Information This DTC indicates an open circuit in the transmission solenoid power control 2 (TSPC2) circuit. PCM P2760:00 Torque Converter Clutch Pressure Control Solenoid Intermittent: No Sub Type Information This DTC indicates a TCC solenoid fault, but the fault did not last long enough to set a more specific DTC. PCM P2769:00 Torque Converter Clutch Circuit Low: No Sub Type Information This DTC indicates a short to ground in the TCC solenoid circuit. PCM P2770:00 Torque Converter Clutch Circuit High: No Sub Type Information This DTC indicates a short to power in the TCC solenoid circuit. Possible Sources
- Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
- Circuit open or shorted
- Transmission internal wiring harness
- TCC solenoid
- LPC solenoid
- PCM
- G1 CHECK THE TRANSMISSION SOLENOID POWER CONTROL 2 (TSPC2) CIRCUIT FOR AN OPENNOTE: This pinpoint test is written to address both TCC solenoid and LPC solenoid electrical faults. For each test step, only the circuits related to the DTC retrieved during the KOEO test need to be tested.
- Ignition OFF.
- Disconnect Transmission vehicle harness C168A.
- Disconnect PCM C175T.
- Inspect the connectors for damaged or pushed out terminals, corrosion, loose wires and missing or damaged seals.
Is the resistance less than 3 ohms?
Yes GO to G2 No REPAIR the open circuit. - G2 CHECK THE TRANSMISSION SOLENOID POWER CONTROL 2 (TSPC2) CIRCUIT FOR A SHORT TO GROUND
- Measure:
Positive Lead Measurement / Action Negative Lead C168A-11 Ground
Is the resistance greater than 10, 000 ohms?
Yes GO to G3 No REPAIR the short to ground. - Measure:
- G3 CHECK THE SOLENOID CONTROL CIRCUIT FOR AN OPEN
Is the resistance less than 3 ohms on the suspect circuit?
Yes GO to G4 No REPAIR the open circuit. - G4 CHECK THE SOLENOID CONTROL CIRCUIT FOR A SHORT TO GROUND
- For the TCC solenoid, measure:
Positive Lead Measurement / Action Negative Lead C168A-25 Ground
- For the LPC solenoid, measure:
Positive Lead Measurement / Action Negative Lead C168A-24 Ground
Is the resistance greater than 10, 000 ohms on the suspect circuit?
Yes GO to G5 No REPAIR the short to ground - For the TCC solenoid, measure:
- G5 CHECK THE SOLENOID CONTROL CIRCUIT FOR A SHORT TO POWER
- Ignition ON.
- For the TCC solenoid, measure:
Positive Lead Measurement / Action Negative Lead C168A-25 Ground
- For the LPC solenoid, measure:
Positive Lead Measurement / Action Negative Lead C168A-24 Ground
Is any voltage present on the suspect circuit?
Yes REPAIR the short to power. No GO to G6 - G6 CHECK THE TRANSMISSION INTERNAL WIRING HARNESS CIRCUITS FOR AN OPEN
- Ignition OFF.
- Drain the transmission fluid and remove the transmission fluid pan. REFER to: Transmission Fluid Pan, Gasket and Filter .
- Disconnect TCC solenoid C1841.
- Disconnect LPC solenoid C1840.
- For the TCC solenoid, measure:
Positive Lead Measurement / Action Negative Lead Transmission component side, pin 11 C1841-1 Transmission component side, pin 25 C1841-2
- For the LPC solenoid, measure:
Positive Lead Measurement / Action Negative Lead Transmission component side, pin 11 C1840-1 Transmission component side, pin 24 C1840-2
Are the resistances less than 3 ohms on the suspect circuits?
Yes GO to G7 No INSTALL a new transmission internal wiring harness (both pieces). REFER to: Transmission Internal Wiring Harness . - G7 CHECK THE TRANSMISSION INTERNAL WIRING HARNESS CIRCUITS FOR A SHORT TO GROUND
- For the TCC solenoid, measure:
Positive Lead Measurement / Action Negative Lead Transmission component side, pin 11 Ground Transmission component side, pin 25 Ground
- For the LPC solenoid, measure:
Positive Lead Measurement / Action Negative Lead Transmission component side, pin 11 Ground Transmission component side, pin 24 Ground
Are the resistances greater than 10, 000 ohms on the suspect circuits?
Yes GO to G8 No INSTALL a new transmission internal wiring harness (both pieces). REFER to: Transmission Internal Wiring Harness . - For the TCC solenoid, measure:
- G8 CHECK THE SOLENOID CONTROL CIRCUIT FOR AN OPEN WITH THE TRANSMISSION VEHICLE HARNESS CONNECTED
- Connect Transmission vehicle harness C168A.
Is the resistance less than 3 ohms on the suspect circuit?
Yes GO to G9 No There is a terminal fitment issue. REPAIR any loose, damaged or bent terminals. - G9 CHECK THE TRANSMISSION SOLENOID POWER CONTROL 2 (TSPC2) CIRCUIT FOR AN OPEN WITH THE TRANSMISSION VEHICLE HARNESS CONNECTED
Is the resistance less than 3 ohms on the suspect circuit?
Yes INSTALL a new solenoid. REFER to: Shift Solenoids (SS) . No There is a terminal fitment issue. REPAIR any loose, damaged or bent terminals.