Chevrolet Trax: DTC P2719-P2721

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 P2719

Pressure Control Solenoid Valve 4 Performance

DTC P2720

Pressure Control Solenoid Valve 4 Control Circuit Low Voltage

DTC P2721

Pressure Control Solenoid Valve 4 Control Circuit High Voltage

Circuit/System Description

Pressure control solenoid valve 4 is part of the control solenoid valve assembly which has no serviceable components. The normally low pressure control solenoid valve 4 regulates and directs oil pressure to the 2-6 clutch regulator valve. Increasing pressure control solenoid valve 4 pressure increases pressure to the 2-6 clutch.

The transmission control module (TCM) varies current to the pressure control solenoid valve 4 by controlling the amount of time the low side driver is ON and OFF. Increasing the ON time increases current to the pressure control solenoid valve 4. Increasing current to pressure control solenoid valve 4 increases oil pressure by closing off the solenoid valve exhaust port. Decreasing the current to the pressure control solenoid valve 4 decreases oil pressure by opening the exhaust port. Pressure control solenoid valve 4 power 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 400-7,500 RPM for 5 s.
• Ignition voltage is 9-32 V.
• DTC runs continuously when above conditions are met.

Conditions for Setting the DTC

P2719

TCM detects an internal electrical performance malfunction on the clutch pressure solenoid valve 4 control circuit where the measured clutch pressure control solenoid valve 4 current does not equal the commanded clutch pressure control solenoid valve 4 current for 5 s.

P2720

TCM detects a short to ground on the clutch pressure control solenoid valve 4 control circuit for 1 s.

P2721

TCM detects an open or short to voltage on the clutch pressure control solenoid valve 4 control circuit for 1 s.

Action Taken When the DTC Sets

P2719

• P2719 is a Type C DTC.
• TCM freezes transmission adaptive functions on the 2-6 clutch.

P2720

• P2720 is a Type A DTC.
• TCM limits the transmission to 2nd gear and reverse.
• TCM commands maximum line pressure.
• TCM freezes transmission adaptive functions.
• TCM inhibits neutral idle.
• TCM inhibits auto grade braking.
• TCM inhibits Tap Up/Tap Down function.
• TCM inhibits manual up, manual down shifts with the shift selector.
• TCM commands 2nd gear if the transmission is in a forward gear and the output speed is less than 700 RPM, or neutral if the output speed is 700 RPM or greater.

P2721

• P2721 is a Type A DTC.
• TCM limits the transmission to 3rd gear and reverse.
• TCM commands maximum line pressure.
• TCM freezes transmission adaptive functions.
• TCM inhibits neutral idle.
• TCM inhibits Tap Up/Tap Down function.
• TCM inhibits manual shifting of forward gears.

Conditions for Clearing the DTC

• P2719 is a Type C DTC.
• P2720 and P2721 are Type A DTCs.

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 second gear long enough to ensure at least a 3ºC (5ºF) rise in TCM temperature.
2. Operate the vehicle in drive range. Allow the transmission to shift through all forward gear ranges.
3. Ignition ON.
4. Verify the scan tool parameters listed below do not display Malfunction:

• Pressure Control Solenoid Valve 4 Performance Test Status
• Pressure Control Solenoid Valve 4 Control Circuit Low Voltage Test Status
• Pressure Control Solenoid Valve 4 Control Circuit High Voltage Test Status

If Malfunction is displayed

Refer to Circuit/System Testing.

If Malfunction is not displayed

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

If the DTC sets

Refer to Circuit/System Testing.

If the DTC does not set

7. 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:

• Pressure Control Solenoid Valve 2 Performance Test Status
• Pressure Control Solenoid Valve 2 Control Circuit Low Voltage Test Status
• Pressure Control Solenoid Valve 2 Control Circuit High Voltage Test Status

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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