2ML70 - Automatic Transmission

DTC P0796 or P0797

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.

DTC Descriptors
DTC P0796
- Pressure Control (PC) Solenoid 3 - Stuck Off

DTC P0797
- Pressure Control (PC) Solenoid 3 - Stuck On

Circuit/System Description

The clutch pressure control solenoid 3 is part of the control solenoid valve assembly and is not serviced separately. The transmission control module (TCM) supplies 12 V to the clutch pressure control solenoid 3 on the high side driver 1 circuit. The TCM controls the clutch pressure control solenoid 3 through the clutch pressure control solenoid 3 control circuit. The normally high clutch pressure control solenoid 3 controls fluid to hybrid low, 1-2 and the 4th clutch assemblies when commanded ON and exhausts fluid when commanded OFF. The clutch pressure control solenoid 3 regulates the transmission fluid pressure to the hybrid low, 1-2 and the 4th clutch assemblies.

Conditions for Running the DTC

P0796 or P0797
* The engine run time is greater than 1 second.
* Shift solenoid valve 1 is not in a transition state.
* The transmission line pressure is greater than 370 kPa (54 psi) and not fluctuating by greater than 30 kPa (4 psi).
* Propulsion is active.

P0796

The clutch pressure control solenoid 3 commanded pressure is greater than 1800 kPa (261 psi) for 4.5 seconds.

P0797

The clutch pressure control solenoid 3 commanded pressure is less than 5 kPa (1 psi) for 4.5 seconds.

Conditions for Setting the DTC

P0796 - Condition 1

The clutch pressure control solenoid 3 commanded pressure is 1800 kPa (261 psi) and the TFP switch 1 state is Low for 30 seconds.

P0766 - Condition 2

The clutch pressure control solenoid 3 commanded pressure is 1800 kPa (261 psi) and the TFP switch 1 state is Low for 0.5 seconds greater than 5 times during a key cycle.

P0797 - Condition 1

The clutch pressure control solenoid 3 commanded pressure is 5 kPa (1 psi) and the TFP switch 1 state is High for 36 seconds.

P0797 - Condition 2

The clutch pressure control solenoid 3 commanded pressure is 5 kPa (1 psi) and the TFP switch 1 state is High for 1.25 seconds greater than 5 times during a key cycle.

Action Taken When the DTC Sets

* P0796 and P0797 are Type B DTCs.
* The transmission control module commands maximum line pressure.
* The transmission control module freezes transmission adaptive functions.

Conditions for Clearing the DTC

P0796 and P0797 are Type B DTCs.

Diagnostic Aids

When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions.

Circuit/System Verification

1. Verify DTC P0721, P0722, P0723, P0966, P0967, P0969, P0970, P0971, P0973, P0974, P0976, P0977, P2720, P2721, P2728, P2729, or P2730 is not set.

• If the DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).

2. Perform the Line Pressure Check (Line Pressure Check).
3. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection).
4. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test (Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test).
5. Inspect the control valve upper body assembly for sticking valves, damage, scored bores, or debris.

• If a concern is found in the valve body, repair or replace the valve body as necessary.

6. Inspect the hybrid low, 1-2 clutch assembly for damage.

• If a concern is found in the hybrid low, 1-2 clutch, repair or replace as necessary.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Control Solenoid Valve and Transmission Control Module Assembly Replacement (Control Solenoid Valve and Transmission Control Module Assembly Replacement).
* Hybrid Low, 1-2 Clutch Piston Removal ()and Hybrid Low, 1-2 Clutch Piston Installation () for Low and Hybrid Low, 1-2 Clutch Assembly repair or replacement.
* Control Module References (Control Module References) for Control Solenoid Valve Assembly replacement, programming and setup.