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 Descriptors

DTC P0973 : Shift Solenoid (SS) 1 Control Circuit Low Voltage
DTC P0974: Shift Solenoid (SS) 1 Control Circuit High Voltage
DTC P0976: Shift Solenoid (SS) 2 Control Circuit Low Voltage
DTC P0977: Shift Solenoid (SS) 2 Control Circuit High Voltage
DTC P0979: Shift Solenoid (SS) 3 Control Circuit Low Voltage
DTC P0980: Shift Solenoid (SS) 3 Control Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Signal | P0973, P0976, P0979 | P0974, P0977, P0980 | P0974, P0977, P0980 | --

### Circuit/System Description

The shift solenoids (SS) are installed directly in the transmission valve body (V/B). The vehicle gear range is determined by various combinations of the shift solenoid states. Each shift solenoid is controlled, driven, by the transmission control module (TCM).

### Conditions for Running the DTC

• | The engine speed is running for 2 seconds.

• | The transmission is not in Emergency Mode.

### Conditions for Setting the DTC

The TCM detects that the shift solenoid actual state does not match the commanded state for 0.5 second.

### Action Taken When the DTC Sets

#### P0973-P0974 and P0976-P0977

• | Type A DTC.

• | The transmission will operate in 4th gear in D range, Reverse in R range.

#### P0979 and P0980

• | Type A DTC.

• | Inhibit adaptive shift control.

• | No neutral control.

• | No garage control.

### Conditions for Clearing the DTC

DTC P0973-P0974, P0976-P0977, and P0979-P0980 are Type A DTCs.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Transmission General Information

#### 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

### Circuit/System Verification

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. Ignition ON, observe the DTC information with a scan tool.

### Circuit/System Testing

1. Ignition OFF, disconnect the transmission wiring harness at the transmission.
2. Test for 10-18 ohms between the shift solenoid control circuit terminal, transmission side, and ground.

⇒ | If not within the specified range.

3. Remove the appropriate solenoid and test for 10-18 ohms across the solenoid.

⇒ | If not within the specified range, replace the valve body assembly.

⇒ | If within the specified range, replace the internal wiring harness.

4. Connect a test lamp between the shift solenoid high control circuit. TCM side, and the ground.
5. Command the shift solenoid ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp does not follow the commanded states, replace the TCM.

### Component Testing

1. Test the shift solenoid, at 20°C (68°F), for 10-18 ohms across the solenoid.

⇒ | If not within the specified range, replace the valve body assembly.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Control Module References for TCM replacement, setup and programming

• | Wiring Harness Removal

• | Wiring Harness Installation