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 P0801: Reverse Lockout Solenoid Control Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
B+ Circuit to Reverse Lockout Solenoid | P0801 | P0801 | -- | --
Reverse Lockout Solenoid Control Circuit | P0801 | P0801 | P0801 | --

### Typical Scan Tool Data

#### Reverse Inhibit Solenoid

Circuit | Short to Ground | Open/High Resistance | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Engine Running. Parameter Normal Range: ON or OFF.
Reverse Inhibit Solenoid Command | OFF | OFF | OFF

### Circuit/System Description

Battery voltage (B+) is supplied directly to the reverse lockout solenoid. The engine control module (ECM) controls the reverses lockout solenoid by grounding the control circuit via an internal switch called a low side driver. The low side driver has a fault line which monitors the control circuit. When the ECM commands the reverse lockout solenoid ON, the voltage on the control circuit should be low, near 0 volts. When the ECM commands the control circuit to the reverse lockout solenoid OFF, the voltage should be high, near battery voltage.

### Conditions for Running the DTC

• | The engine is running.

• | The vehicle speed is less than 3 km/h (2 mph).

### Conditions for Setting the DTC

• | The ECM detects that the commanded state of the driver and the actual state of the control circuit does not match.

• | The condition exists for 2 seconds.

### Action Taken When the DTC Sets

P0801 is a Type C DTC.

### Conditions for Clearing the MIL/DTC

P0801 is a Type C DTC.

### Diagnostic Aids

• | The battery must be fully charged and pass a battery test. Refer to Battery Inspection/Test.

• | The reverse lockout solenoid is referred to as the reverse inhibit solenoid on the scan tool.

### Reference Information

#### Schematic Reference

Manual Transmission Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Manual Transmission Description and Operation

#### 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

Engine Control Module Scan Tool Information

### Circuit/System Verification

1. Ignition ON, command the reverse lockout solenoid ON and OFF, with a scan tool, while observing the following reverse lockout circuit status parameters.

• | Reverse lockout solenoid control Ckt. Short Gnd Test Status

• | Reverse lockout solenoid control Ckt. Open Test Status

• | Reverse lockout solenoid control Ckt. Short Volts Test Status

⇒ | Each parameter should toggle between OK and Not Run or Not Run and OK.

2. 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

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

1. Disconnect the reverse lockout solenoid harness connector.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal B and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the circuit fuse is open, replace the reverse lockout solenoid.

3. Verify that a test lamp does not illuminate between the B+ circuit terminal B and the control circuit terminal A.

⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.

4. Remove the test lamp.
5. Command the reverse lockout solenoid ON with a scan tool. Verify with a scan tool that the reverse lockout solenoid Ckt. Short Volts Test Status parameter is OK.

⇒ | If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.

6. Install a 3A fused jumper wire between the reverse lockout control circuit terminal A and the B+ circuit terminal B. Command the reverse lockout solenoid ON with a scan tool. Verify with a scan tool that the affected reverse lockout solenoid Ckt. Short Volts Test Status parameter is displaying Fault.

⇒ | If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

7. If all the circuits test normal, test or replace the reverse lockout assembly.

### Repair Instructions

• | Reverse Lockout Solenoid Replacement

• | Engine Control Module Programming and Setup

• | Engine Control Module Replacement or Engine Control Module Replacement

### Repair Verification

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 60 seconds.
5. Engine running, command the reverse lockout solenoid ON and OFF with a scan tool, while observing the reverse inhibit circuit status parameters. The circuit status parameters should change from OK to Not Run or Not Run to OK.

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