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 P0317: Rough Road Signal Not Detected

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-Volt Reference | P1392 | P0317, P1392 | P1393 | P1391
Rough Road Sensor Signal | P1392 | P0317, P1392 | P1393 | P1391
Low Reference | -- | P1391 | -- | P1391

### Typical Scan Tool Data

#### Rough Road Sensor

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Engine operating in Closed Loop Parameter Normal Range: 1.1-3.7 Volts
5-Volt Reference | 0.0 Volts | 0.0 Volts | 5.0 Volts*
Rough Road Sensor Signal | 0.0 Volts | 0.0 Volts | 5.0 Volts*
Low Reference | -- | 0.0 Volts | 5.0 Volts*
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

### Circuit/System Description

The engine control module (ECM) identifies engine misfire by detecting variations in crankshaft speed. Crankshaft speed variations can also occur when a vehicle is operating over a rough road. The ECM receives a rough road signal by a gravity sensing rough road sensor or an electronic brake control module (EBCM), if equipped with the antilock brake system (ABS). The ABS can detect if the vehicle is on the rough surface based on wheel acceleration/deceleration data supplied by each wheel speed sensor. This information is sent to the ECM by the EBCM through a serial data line. The rough road sensor is a vertical low G-acceleration sensor. By sensing vertical acceleration caused by rough road conditions, the ECM determines if the changes in crankshaft speed are due to engine misfire or are driveline induced. The rough road sensor consist of the following circuits:

• | A 5-volt reference

• | A rough road sensor signal

• | A low reference

### Conditions for Running the DTC

• | The engine has been running for greater than 10 seconds.

• | DTC P0317 runs continuously once the above condition is met for greater than 10 seconds.

### Conditions for Setting the DTC

The ECM does not detect a rough road signal for greater than 9 seconds.

### Action Taken When the DTC Sets

DTC P0317 is a Type C DTC.

### Conditions for Clearing the DTC

DTC P0317 is a Type C DTC.

### Diagnostic Aids

• | If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected.

• | The scan tool 5 volt reference parameter should display between 4.8-5.2 volts.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### 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, observe the DTC information with a scan tool. Verify that DTC P0641 or P0651 is not set.

⇒ | If any of the DTCs are set, refer to DTC P0641 or P0651.

2. Engine running, observe the DTC information with a scan tool. DTC P0317 should not set.
3. 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

1. If the vehicle is equipped with ABS, test the circuit between the EBCM and the ECM for an open/high resistance.

⇒ | If the circuit tests normal, refer to Symptoms - Antilock Brake System.

2. Ignition OFF, disconnect the harness connector at the rough road sensor.
3. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A or C and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

Important: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.

4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A or C and ground.

⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM.

⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. Verify the scan tool rough road sensor voltage parameter is less than 0.1 volt.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

6. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit erminal A or C. Verify the scan tool rough road sensor parameter is greater than 4.8 volts.

⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

7. If all circuits test normal, test or replace the rough road sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Rough Road Sensor Replacement

• | Control Module References for engine control module replacement, setup, and programming