Service Information

Volt

DTC P0751

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0751: Shift Solenoid (SS) 1 Valve Performance - Stuck Off

The shift solenoid 1 and transmission control module are part of the control solenoid valve assembly and are not serviced separately. The transmission control module supplies 12 V to shift solenoid 1 on the high side driver 1 circuit. The transmission control module controls the normally closed shift solenoid 1 on the shift solenoid 1 control circuit. The shift solenoid 1 controls the transmission fluid to the shift solenoid valve (523).

Conditions for Running the DTC

•	Any transmission shift or engine On command.

•	Line pressure command is greater than 325 kPa.

Conditions for Setting the DTC

The transmission control module detects shift solenoid valve 1 is OFF when commanded ON.

Action Taken When the DTC Sets

•	P0751 is a Type A DTC.

•	The driver information centre may display ENGINE NOT AVAILABLE SERVICE SOON.

•	The internal combustion engine may not start.

Conditions for Clearing the DTC

P0751 is a Type A DTC.

Reference Information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification

Verify that P0966, P0967, P0969, P0970, P0971, P0973, P0974, P0976, P0977, P2720, P2721, P2728, P2729, or P2730 is not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

Vehicle ON, in Park, open the hood. The internal combustion engine should start and transmission fluid pressure switch 1 on the scan tool should change from Low to High.

⇒	If the engine does not start and the transmission fluid pressure switch 1 parameter does change from Low to High, inspect the control valve body shift solenoid valve (523) for a stuck off condition. Refer to Control Valve Body Diagnostic Inspection .

⇒	If the engine starts and the transmission fluid pressure switch 1 parameter does not change from Low to High, inspect the transmission fluid pressure switch 1 for a stuck Low condition. Refer to Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test .

Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .
Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test .

⇒	If the shift solenoid 1 is found to be leaking or stuck OFF, replace the Q8 control solenoid valve assembly.

⇒	If the control solenoid valve assembly tests normal, inspect the shift solenoid valve (523) and hydraulic circuits for a leak or a stuck valve. Refer to Control Valve Body Diagnostic Inspection .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Control Valve Body Replacement for control valve body replacement.

•	Control Valve Body Diagnostic Inspection

•	Control Module References for Control Solenoid Valve Assembly and Transmission Control Module Assembly replacement, programming, and setup.