• | 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. |
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 |
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+. |
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 |
• | The engine is running. |
• | DTC P0317 runs continuously once the above condition is met for more than 10 seconds. |
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.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
⇒ | If the circuit/connections test normal, refer to Symptoms - Antilock Brake System . |
⇒ | 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.
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 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. |
⇒ | 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. |
⇒ | 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. |
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |