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 DetectedDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5-Volt Reference | P0317 | P0317 | P0317 | -- |
Low Reference | P0317 | P0317 | -- | -- |
Typical Scan Tool Data
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* |
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 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 the rough road signal circuit. The rough road sensor is a wheel speed sensor. The wheel speed sensor produces an alternating current (AC) voltage that increases with wheel speed. The ECM receives a rough road signal from a wheel speed sensor located at the left front wheel. The ECM can determine if the vehicle is on a rough road surface based on the signal from the wheel speed sensor. When the ECM detects a rough road condition, misfire diagnostics will be disabled.
Conditions for Running the DTC
| • | The engine has been running for greater than 10 seconds. |
| • | The vehicle speed is greater than 11 km/h (7 mph). |
| • | The DTC 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
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641 or P0651 is not set.
- Engine running, observe the DTC information with a scan tool. DTC P0317 should not set.
- 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.
| ⇒ | If any of the DTCs are set, refer to DTC P0641 or P0651 . |
Circuit/System Testing
- If the vehicle is equipped with ABS, test the circuit between the EBCM and the ECM for an open/high resistance.
- Ignition OFF, disconnect the harness connector at the rough road sensor.
- Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and ground.
- If all circuits test normal, test or replace the rough road sensor.
| ⇒ | If the circuit tests normal, refer to Symptoms - Antilock Brake System . |
| ⇒ | 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.
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for engine control module replacement, setup, and programming
