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DTC P174A

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 P174A: Pressure Control (PC) Solenoid Low Reference Circuit

Circuit/System Description

This circuit controls the PC solenoid through the TCM. The TCM outputs a duty cycle to control the line pressure. The ground circuit is necessary for controlling the line pressure.

Conditions for Setting the DTC

When the transmission control module (TCM) sends an output duty cycle signal to activate the PC solenoid, but the return signal is received as OFF by the monitoring signal.

Action Taken When the DTC Sets

    • DTC P174A is a Type D DTC.
    • PC solenoid is turned OFF.
    • Line pressure is maximum.

Conditions for Clearing the DTC

DTC P174A is a Type D DTC.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

    •  Electronic Component Description
    •  Transmission Component and System 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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF, disconnect the Q8 Control Solenoid Valve Assembly wiring harness plug and K71 TCM wiring harness plug.
  2. Test for 2.9 Ω at 20°C (68°F) between the Q32 PC Solenoid Valve circuit terminal 3 and 5 or 3 and ground. 
  3. If not the specified value, test the Q23 PC Solenoid Valve signal circuits and ground return circuit for an open circuit, short circuit to voltage or short circuit to ground.
    If the circuit is OK, replace the Q23 PC Solenoid Valve.
  4. Test for continuity between the Q23 PC Solenoid Valve circuit terminal 3 and K71 TCM wiring harness plug terminal 1.
  5. Test for continuity between the Q23 PC Solenoid Valve circuit terminal 5 and K71 TCM wiring harness plug terminal 2.

    If the continuity is not normal, repair or replace the circuit.
    If all circuits and the sensor test normal, replace the K71 TCM.

Component Testing

  1. Disconnect the Q23 PC Solenoid Valve wiring harness plug.
  2. Test for 2.9 Ω at 20°C (68°F) between the PC solenoid valve terminal and the transmission case.
  3. If the resistance is too low or too high, replace the Q23 PC Solenoid Valve.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Pressure Control Solenoid Valve Replacement
    •  Wiring Harness Replacement
    • Control Module References for TCM replacement, setup, and programming
   


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