Diagnostic Instructions

DTC Descriptors

DTC P0756:  2-3 Shift Solenoid (SS) Valve Performance - No First or Second Gear

DTC P0757:  2-3 Shift Solenoid (SS) Valve Performance - No Third or Fourth Gear

Diagnostic Fault Information

Hydraulic Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
1-2 SS Valve	--	--	--	P0751, P0752
2-3 SS Valve	--	--	--	P0756, P0757
TCC PWM Valve	--	--	--	P0741, P0742

Typical Scan Tool Data

2-3 Shift Solenoid (SS) Valve Performance Parameter Data

Circuit	Normal	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: OK
1-2 Sol. CKT Status	OK	Open/Short to GND	Open/Short to GND	Short to Volts
2-3 Sol. CKT Status	OK	Open/Short to GND	Open/Short to GND	Short to Volts
TCC Duty Cycle CKT Status	OK	Open/Short to GND	Open/Short to GND	Short to Volts

Circuit/System Description

The transmission control module (TCM) controls the torque converter clutch pulse width modulation (TCC PWM) solenoid valve. The solenoid controls the hydraulic fluid for TCC apply and release. When the TCC is fully applied, the engine is coupled directly to the transmission through the TCC. The TCC used is an electronically controlled capacity clutch (ECCC). The TCM will normally allow a small amount of slip to occur with the ECCC. When the TCC is engaged, TCC slip speed is maintained at approximately 20-50 RPM. The 1-2 shift solenoid (SS) valve and the 2-3 SS valve are supplied with fused ignition voltage. The ground path is controlled by the TCM. When the TCM commands the solenoid OFF, a ground path is not provided and the filtered line pressure that is fed to the solenoid is exhausted. When the TCM commands the solenoid ON, a ground path is provided and the exhaust port is blocked, stopping the exhaust of line pressure. The TCM identifies a 1-2 SS valve or a 2-3 SS valve condition by monitoring the commanded gear versus gear ratio. Refer to Shift Solenoid Valve State and Gear Ratio .

Conditions for Running the DTC

P0756

P0757

Conditions for Setting the DTC

P0756

The following conditions both occur twice in one trip:

P0756 - Condition 1

The TCM commands 1st gear with the transmission OSS 200 RPM or more, the TCC slip speed is -20 RPM or more, and the gear ratio indicates 4th gear, 0.65:1 to 1.87:1, for 2 seconds.

P0756 - Condition 2

The TCM commands 2nd gear and the gear ratio indicates 3rd gear, 0.95:1 to 1.05:1, for 3 seconds.

P0757

The following conditions both occur twice in one trip:

P0757 - Condition 1

The TCM commands 3rd gear and the gear ratio indicates 2nd gear, 1.54:1 to 1.71:1 for 2 seconds.

P0757 - Condition 2

The TCM commands 4th gear and the gear ratio indicates 1st gear, 1.54:1 to 3.11:1, for 2 seconds.

Action Taken When the DTC Sets

P0756

P0757

Conditions for Clearing the DTC

DTCs P0756 and P0757 are Type A DTCs.

Diagnostic Aids

If the DTC is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist:

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Perform the Transmission Fluid Check to verify correct fluid level and condition. The transmission fluid level should be within the crosshatch band and the transmission fluid should be red or dark brown.

⇒	If the transmission fluid is low or discolored, refer to Automatic Transmission Fluid Filter and Seal Replacement .

2. Operate the vehicle in Drive and ensure that the TCM commands all gears. The ratios should match the commanded gear for all gears. Refer to Shift Solenoid Valve State and Gear Ratio .

⇒	If the gear ratios do not match the commanded gear, inspect the following and repair/replace as necessary:

•	Debris or chips in the accumulator and actuator feed oil passages.

•	Debris or chips restricting oil flow in passage #29 of the case or through the spacer plate gasket into the valve body

•	A cracked 2-3 shift solenoid

•	A 2-3 shift valve which is stuck or hung up in the valve body bore

•	A 2-3 shuttle valve which is stuck or hung up in its bore

•	Damaged seals on the shift solenoid valves. Refer to Shift Solenoid Leak Test for further diagnosis.

3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.