For 1990-2009 cars

### 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 P2670: Solenoid High Control Circuit Group 2 Low Voltage
DTC P2671: Solenoid High Control Circuit Group 2 High Voltage

### Circuit/System Description

The transmission control module (TCM) provides voltage to the pressure control solenoid, the shift solenoids, and the torque converter clutch pulse width modulated (TCC PWM) solenoid through two separate solid-state devices called high side drivers, called HSD1 and HSD2. HSD1 provides electrical power to the pressure control solenoid. HSD2 provides power to the shift solenoids. A normal function of the TCM is to run tests on each driver to ensure that it is functioning properly.

### Conditions for Running the DTC

#### P2670

The engine run time is greater than 5 seconds.

#### P2671

The ignition is ON.

### Conditions for Setting the DTC

#### P2670

The TCM detects a short to ground on the HSD2 circuit when the HSD2 is commanded ON.

#### P2671

The TCM detects greater than 6.4 volts at the HSD2 terminal prior to commanding the HSD2 ON.

### Action Taken When the DTC Sets

• | DTC P2670 and P2671 are Type B DTCs.

• | The TCM turns off power to all solenoids.

• | The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.

• | The TCM commands maximum line pressure.

• | The TCM freezes transmission adaptive functions.

• | The TCC is disabled.

### Conditions for Clearing the DTC

DTC P2670 and P2671 are Type B DTCs.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

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

#### Scan Tool Reference

Transmission Control Module Scan Tool Information

### Circuit/System Testing

1. Clear the DTC and operate the vehicle under the conditions for running and setting the DTC.
2. Observe the High Side Driver CKT Status parameter. The parameter should display OK.

⇒ | If the parameter displays Open, Short to Ground, Short to Voltage, or the DTC resets, replace the control solenoid (w/body and TCM) valve assembly. Refer to Control Module References for replacement, setup, and programming.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | 1-2 Shift Solenoid Valve Replacement

• | 2-3 Shift Solenoid Valve Replacement

• | 4-5 Shift Solenoid Valve Replacement

• | Torque Converter Clutch Solenoid Replacement

• | Transmission Internal Electrical Harness Replacement

• | Control solenoid (w/body and TCM) valve assembly replacement. Refer to Control Module References for replacement, setup and reprogramming.