Symptoms

- Engine Light ON (or Service Engine Soon Warning Light) - Shift shock

Possible Causes

- Low transmission fluid level - Dirty transmission fluid - Faulty pressure control solenoid valve - Pressure control solenoid valve harness or connectors - Pressure control solenoid valve circuit is open or shorted

When Detected

The P0799 is triggered when the ECM detects an intermittent circuit in shift solenoid valves

Description

The Engine Control Module (ECM) uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear). Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical troubles of the shift solenoid valves and valve body.