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 provide 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 Volts¹
Rough Road Sensor Signal | 0.0 Volts | 0.0 Volts | 5.0 Volts¹
Low Reference | -- | 0.0 Volts | 5.0 Volts¹
¹ 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 more than 10 seconds.

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

### Conditions for Setting the DTC

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

### Action Taken When the DTC Sets

DTC P0317 is a Type C DTC.

### Conditions for Clearing the MIL/DTC

DTC P0317 is a Type C DTC.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Start the engine. Observe the DTC information with a scan tool. DTC P0317 should not set.
2. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

### 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/connections test normal, refer to Symptoms - Antilock Brake System .

2. Ignition OFF, disconnect the harness connector of the rough road sensor.
3. Ignition ON, verify that the rough road sensor parameter is less than 0.1 volt.

⇒ | If greater than 0.1 volt, test the signal circuit of the rough road sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.

Important: The test lamp is used to load the circuit and may not illuminate.

4. Ignition ON, connect a test lamp between the 5-volt reference circuit of the rough road sensor and ground.

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.

5. Test for 4.8-5.2 volts between the 5-volt reference circuit of the rough road sensor and ground.

⇒ | If less than 4.8 volts, test the 5-volt reference circuit of the rough road sensor for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM.

⇒ | If greater than 5.2 volts, test the 5-volt reference circuit of the rough road sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.

6. Ignition ON, test for less than 0.2 volt between the low reference circuit of the rough road sensor and ground.

⇒ | If greater than 0.2 volt, test the low reference circuit of the rough road sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.

7. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit of the rough road sensor and ground.

⇒ | If greater than 5 ohms, test the low reference circuit of the rough road sensor for an open/high resistance. If the circuit/connections test normal, replace the ECM.

8. Ignition ON, install a 3-amp fused jumper wire between the signal circuit and the 5-volt reference circuit of the rough road sensor to verify that the rough road sensor parameter is greater than 4.8 volts.

⇒ | If less than 4.8 volts, test the signal circuit of the rough road sensor for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.

9. If all circuits/connections test normal, 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