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:

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

DTC P0317 is a Type C DTC.

DTC P0317 is a Type C DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Start the engine, observe the DTC information with a scan tool. DTC P0317 should not set.

1. If the vehicle is equipped with an anti-lock brake system (ABS), test the circuit between the electronic brake control module (EBCM) and the electronic control module (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 volts.

⇒	If greater than 0.1 volts, test the signal circuit of the rough road sensor for a short to voltage. If the circuit/connections test normal, replace the engine control module (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 volts between the low reference circuit of the rough road sensor and ground.

⇒	If greater than 0.2 volts, 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 engine control module (ECM).

9. If all circuits/connections test normal, replace the rough road sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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