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 Descriptors

DTC P0659: Solenoid High Control Circuit Group 1 High Voltage

DTC P2671: Solenoid High Control Circuit Group 2 High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

HSD1 B+

P0658

P0657

P0659

--

HSD2 B+

P2670

P2669

P2671

--

Circuit/System Description

The transmission control module (TCM) provides B+ to the modulated main (MOD MAIN) pressure control solenoid, the torque converter clutch (TCC) pressure control solenoid, and the pressure control solenoid 1 (PCS1), through a separate solid state device called high side driver 1 (HSD1). The TCM also provides B+ to the pressure control solenoid 2 (PCS2) and shift solenoids (SS) 1, 2, and 3 through a separate solid state device called high side driver 2 (HSD2). The TCM uses low side drivers to control the solenoids.

Conditions for Running the DTC

The test runs during TCM initialization.

Conditions for Setting the DTC

The DTC sets when the TCM detects a voltage on the HSD1 or HSD2 circuit greater than 6 V with the driver circuits off.

Action Taken When the DTC Sets

    • The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL).
    • DTC P0659 or P2671 is stored in TCM history.
    • While diagnostic response is active, if the shift selector is moved to NEUTRAL, the transmission will shift to NEUTRAL. If the shift selector is moved to REVERSE, the transmission will shift to REVERSE. If the shift selector is moved to a forward range, the transmission will shift to third range.
    • The TCM inhibits TCC engagement.

Conditions for Clearing the DTC

DTCs P0659 and P2671 are Type A DTCs.

Diagnostic Aids

DTCs P0659 and P2671 will only set during TCM initialization, so a road test would not duplicate the problem.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

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

  1. Ignition ON, clear the DTCs with a scan tool.
  2. Ignition OFF, open the driver’s door.
  3. Ignition ON, verify with a scan tool that DTCs P0659 or P2671 are not set.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

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

  1. Ignition ON, clear the DTCs with a scan tool.
  2. Ignition OFF, disconnect the X175 harness connector at the transmission.
  3. Ignition ON, use a scan tool and verify that DTC P0659 or P2671 did not set.
  4. If DTCs P0659 or P2671 did not set, replace the internal transmission wire harness. Refer to Wiring Harness Replacement.
    If DTCs P0659 or P2671 do set, test the affected B+ circuit for a short to voltage. If the circuit tests normal, replace the TCM. Refer to Control Module References for TCM replacement, setup, and programming.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Wiring Harness Replacement
    •  Control Module References for TCM replacement, setup, and programming.

Repair Verification

If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.