Chevrolet Trax: DTC P0973 OR P0974

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 Descriptors

DTC P0973

Shift Solenoid Valve 1 Control Circuit Low Voltage

DTC P0974

Shift Solenoid Valve 1 Control Circuit High Voltage

Circuit/System Description

The shift solenoid valve 1 is part of the control solenoid valve assembly which has no serviceable components.

Shift solenoid valve 1 is a normally closed ON/OFF solenoid and is controlled by the transmission control module (TCM) through a low side driver. When the shift solenoid valve 1 is energized (ON), fluid pressure is directed to the clutch select valve. Power to shift solenoid valve 1 is supplied by the TCM through a high side driver. The high side driver protects the circuit and components from excessive current flow. If excessive current flow is detected, the high side driver will turn OFF. When the fault is corrected, the high side driver will reset.

Conditions for Running the DTC

• Engine speed is 400-7500 RPM for 5 s.
• Ignition voltage is 9-32 V.

Conditions for Setting the DTC

P0973

TCM detects a short to ground on the shift solenoid valve 1 control circuit for 2 s.

P0974

TCM detects an open or short to voltage on the shift solenoid valve 1 control circuit for 2 s.

Action Taken When the DTC Sets

P0973

• DTC P0973 is a Type A DTC.
• TCM freezes transmission adaptive functions.
• TCM commands maximum line pressure.
• TCM limits the transmission to neutral or 2nd gear and reverse.
• TCM inhibits neutral idle.
• TCM inhibits auto grade braking.
• TCM inhibits the Tap Up/Tap Down function.
• TCM inhibits manual shifting of forward gears.

P0974

• DTC P0974 is a Type B DTC.
• TCM inhibits 1st gear.
• TCM inhibits neutral idle.

Conditions for Clearing the DIC/DTC

• DTC P0973 is a Type A DTC.
• DTC P0974 is a Type B DTC.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics (Encore, MH8 or MHB) , Automatic Transmission Controls Schematics (Trax, MH8 or MHB)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

• Inline Harness Connector End Views (Encore) , Inline Harness Connector End Views (Trax)

Description and Operation

• Electronic Component Description
• Transmission Component and System Description
• Transmission General Description

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

DT-48616-10 Adapter Harness

For equivalent regional tools, refer to Special Tools

Circuit/System Verification

1. Operate the vehicle in 2nd gear long enough to ensure at least a 3ºC (5ºF) rise in TCM temperature.
2. Place the gear selector in Reverse for 5 s and then idle vehicle for 5 s.
3. Verify the scan tool parameters listed below do not display Malfunction:

• Shift Solenoid Valve 1 Control Circuit Low Voltage Test Status
• Shift Solenoid Valve 1 Control Circuit Open Test Status
• Shift Solenoid Valve 1 Control Circuit High Voltage Test Status

If Malfunction is displayed

Refer to Circuit/System Testing.

If Malfunction is not displayed

4. 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.
5. Verify the DTC does not set.

If the DTC sets

Refer to Circuit/System Testing.

If the DTC does not set

6. All OK.

Circuit/System Testing

NOTE: You must perform the Circuit/System Verification first.

1. Ignition OFF, remove the Q8 Control Solenoid Valve Assembly.
2. Verify the Q8 Control Solenoid Valve Assembly is not contaminated with any debris and clean as necessary. Refer to Control Solenoid Valve and Transmission Control Module Assembly Inspection.

If contaminated

Repair as necessary.

If not contaminated

3. Verify the resistance is within the specified range for each solenoid valve listed in the Control Solenoid Valve and Transmission Control Module Assembly Inspection.

If the resistance is not within range

Replace the Q8 Control Solenoid Valve Assembly

If the resistance is within range

4. Place the Q8 Control Solenoid Valve Assembly on a clean work surface near the transmission assembly.
5. Connect the DT-48616-10 adapter harness between the vehicle harness connector and the Q8 Control Solenoid Valve Assembly connector. Ignition ON.
6. Verify the scan tool parameters listed below do not display Malfunction:

• Shift Solenoid Valve 1 Control Circuit Low Voltage Test
• Shift Solenoid Valve 1 Control Circuit Open Test
• Shift Solenoid Valve 1 Control Circuit High Voltage Test

If Malfunction is displayed

Replace the Q8 Control Solenoid Valve Assembly.

If Malfunction is not displayed

7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Perform the Transmission Adaptive Values Learn following all transmission repairs
• Control Module References - for Control Solenoid Valve Assembly replacement, programming and setup

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