GM Service Manual Online
For 1990-2009 cars only

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 P1702: Transmission Clutch 1 Stuck On - Engagement

DTC P1703: Transmission Clutch 1 Stuck On - No Control

DTC P1704: Transmission Clutch 1 Slip Detected

Diagnostic Fault Information

Component

Condition

DTCs

Valve Body Assembly

    • incorrect transmission fluid level
    • clogged hydraulic system
    • plugged or restricted passages
    • gasket leaking

P1702, P1703, P1704

Clutch Pressure Control Solenoid Valve

    • incorrect transmission fluid level
    • clogged hydraulic system
    • mechanically stuck in the applied position
    • gasket leaking

P1702, P1703, P1704

Typical Scan Tool Data

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Engine running, normal operating temperature

Parameter Normal Range: 0.1 A to 1.1 A

Signal

0 A

2.55 A

2.55 A

Low Reference

--

2.55 A

1

1. Internal TCM damage may occur if shorted to B+

Circuit/System Description

When the vehicle is stopped in range D, the transmission enters a neutral condition by releasing the clutch C1. By reducing drag loss of the torque converter, the load on the engine is lightened, fuel economy is enhanced, and idling vibration is reduced.

Conditions for Running the DTC

P1702, P1703, P1704

    • The ignition voltage is between 10.2 V and 15.5 V.
    • The engine speed is greater than 400 RPM for 2 s.
    • The transmission is not in emergency mode.
    • Driving in D range.
    • Transmission control module (TCM) communication is normal.
    • Transmission Fluid temperature is more than 10°C (50°F).

Conditions for Setting the DTC

P1702

    • Clutch C1 hydraulic pressure is less than 26 kPa (3.8 PSI).
    • Input revolution is less than 400 RPM for more than 5 s.

P1703

    • Clutch C1 IN-NEUTRAL control
    • Clutch C1 hydraulic pressure is more than 350 kPa (51 PSI).
    • Input revolution is more than 400 RPM for more than 0.6 s.

P1704

    • Clutch C1 apply control
    • C1 hydraulic pressure command value is more than 300 kPa (44 PSI).
    • Determined after 1 time lasting more than 0.3 s.

Action Taken When the DTC Sets

P1702, P1703

    • DTCs P1702, P1703 are Type C DTC.
    • No self learning function.
    • No Neutral control.
    • No adaptive shift.
    • Inhibit of Neutral control and garage shift control (N-D,D-N,N-R,R-N).

P1704

    • DTC P1704 is Type B DTCs.
    • Torque limitation.
    • The TCM turns OFF all solenoids.
    • The TCM allows the vehicle to operate only in second gear and "R" range after a stop.

Conditions for Clearing the DTC

P1702

    • DTC P1702 is Type C DTC.
    • Clutch C1 IN-NEUTRAL control
    • Clutch C1 pressure is more than 26 kPa (3.8 PSI).

P1703

    • DTC P1703 is Type C DTC.
    • Clutch C1 IN-NEUTRAL control
    • Clutch C1 hydraulic pressure is less than 350 kPa (51 PSI).

P1704

    • DTC P1704 is Type B DTCs.
    • C1 hydraulic pressure command value is less than 300 kPa (44 PSI).

Diagnostic Aids

When attempting to set solenoid electrical DTCs, ensure the TCM is warmed up and the transmission is operated in 2nd gear long enough to ensure a 3°C (5°F) increase in TCM substrate temperature. This will place the TCM under the optimal conditions to test solenoid electrical DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

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

Description and Operation

Transmission Component and System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
  2. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in transmission fluid temperature, then operate the vehicle in Park for 5 s.
  3. Observe the scan tool data Clutch Pressure Control Solenoid Valve 1 Current parameter, the reading should be between 0.1 A - 1.1 A.

Circuit/System Testing

Command the Clutch PC Solenoid Valve 1 Increase and Decrease with a scan tool. The value should rise from 0.1 A - 1.1 A and return to 0.1 A.

If the value does not change, turn ignition OFF, remove the K71 Transmission Control Module (TCM). Connect a test lamp between the low reference circuit terminal 10 (X2) at the K71 Transmission Control Module (TCM) and the voltage supply component circuit terminal 11 (X2) at the K71 Transmission Control Module (TCM). Command the Clutch PC Solenoid Valve 1 Increase and Decrease with a scan tool. The test lamp has to illuminate brighter with increasing current.
If the test lamp always illuminate or always does not illuminate, replace the K71 Transmission Control Module (TCM).

Component Testing

Dynamic Test

  1. Perform the line pressure check Line Pressure Check
  2. If the line pressure check fails, replace the control valve body.
  3. Verify the line pressure check does not fail.
  4. If the line pressure check fails, replace the replace the K71 Transmission Control Module (TCM).
  5. Perform the control solenoid valve inspection Control Solenoid Valve Inspection.
  6. If the inspection fails, replace the control valve body.
  7. If all circuit test normal, replace the replace the K71 Transmission Control Module (TCM).

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    • Control valve body replacement. Refer to Control Valve Body Replacement for replacement, setup and programming.
    • TCM, refer to Control Module References for replacement, setup and programming.
       ⇒Perform the Transmission Adaptive Functions.