MVA 4 Speed - Automatic Transmission

DTC P2769 or P2770

Circuit Description

The shift solenoid valve DSL is turned ON and OFF by signals from the engine control module (ECM) in order to control the hydraulic pressure operation, the lock-up relay valve, which then controls operation of the lock-up clutch.

Torque converter lock-up is controlled by the ECM based on engine rpm, engine load, engine temperature, vehicle speed, transmission temperature, and shift range selection. The ECM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to the input turbine rpm (NT). The ECM calculates the actual transmission gear by comparing input turbine rpm (NT) to counter gear rpm (NC). When conditions are appropriate, the ECM requests lock-up by applying control voltage to the shift solenoid DSL. When the DSL is opened, it applies pressure to the lock-up relay valve and locks the torque converter clutch. If the ECM detects an open or short in the DSL solenoid circuit, the ECM interprets this as a fault in the DSL solenoid or circuit. The ECM will illuminate the MIL and store the DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

* DTC P2769 Torque Converter Clutch Solenoid Circuit Low (Shift Solenoid Valve DSL)
* DTC P2770 Torque Converter Clutch Solenoid Circuit High (Shift Solenoid Valve DSL)

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

P2769

The ECM detects short in solenoid valve DSL circuit when solenoid valve DSL is operated.

P2770

The ECM detects an open in solenoid valve DSL circuit when solenoid valve DSL is not operated.

Action Taken When the DTC Sets

* DTCs P2769 and P2770 are type C DTCs.
* The malfunction indicator lamp (MIL) illuminates the first time the diagnostic runs with the fault active.

Conditions for Clearing the MIL/DTC

The DTC will clear when conditions for setting the DTC have been repaired.