Circuit Description
Rough roads cause torque on the tires that is transmitted to the powertrain. This slows down the crankshaft giving the appearance of a misfire. The electronic brake and traction control module (EBTCM) determines rough road surfaces using input from the wheel speed sensors. The EBTCM then sends the rough road data to the powertrain control module (PCM) on the serial data circuit. The PCM uses the rough road data to enhance the misfire diagnostic. The data allows the PCM to distinguish the crankshaft speed variations caused by rough road surfaces from those caused by true misfires. If the EBTCM is unable to identify rough road conditions while the PCM detects a misfire condition, DTC P1380 will set.
Conditions for Running the DTC
| • | The engine load is less than 100 percent. |
| • | The engine speed is less than 6,500 RPM. |
| • | The vehicle speed is more than 1 km/h (0.6 mph). |
| • | A misfire DTC is occurring and requesting the malfunction indicator lamp (MIL) to be illuminated. |
Conditions for Setting the DTC
The PCM detects an EBTCM rough road sensing error.
Action Taken When the DTC Sets
| • | The PCM will not illuminate the malfunction indicator lamp (MIL). |
| • | The PCM will store the conditions present when the DTC set as Failure Records data only. |
Conditions for Clearing the MIL/DTC
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Diagnostic Aids
If the condition is intermittent, refer to Intermittent Conditions .
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Diagnostic System Check - ABS in Antilock Brake Systems | |
