Chevrolet P1380 Code: Misfire Detected – Rough Road Data Not Available
A misfire was detected, and the ABS module couldn't supply rough-road data to confirm it wasn't just bumps.
Safety first · Consult a professional
- Braking system affected: ABS may be disabled. Drive carefully and have it checked promptly.
At a glance
Severity: Moderate
- Meaning
- Misfire Detected – Rough Road Data Not Available
- System
- Ignition & Misfire · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $80–$1,100
- DIY difficulty
- Moderate
GM's misfire monitor looks for tiny speed dips in the crankshaft, but driving over washboard gravel or potholes can shake the drivetrain enough to mimic a misfire. To filter that out, the PCM on many older Chevrolets receives a rough-road signal from the ABS/traction module (EBCM or EBTCM), which calculates it from the wheel speed sensors. P1380 sets when the PCM is already recording a misfire that is about to turn on the check engine light, and the EBCM reports that its rough-road data is invalid, typically because the ABS module has its own fault. So P1380 always comes with two tasks: diagnose the misfire code stored next to it, and fix whatever is stopping the ABS module from producing valid data.
Can I keep driving? Drive gently and not far until both issues are checked. A real misfire can overheat the catalytic converter, and if the ABS or traction light is also on, your anti-lock braking may be disabled, so leave more stopping distance.
How to read P1380
- P Powertrain
- 1 Manufacturer-specific
- 3 Ignition / misfire
- 80 Specific fault
Symptoms
- Check engine light, stored together with a P030x misfire code
- ABS and/or traction control light on
- Rough running, shaking at idle or under load (if the misfire is real)
- ABS module codes such as a wheel speed sensor fault
- Sometimes no noticeable misfire at all when the rough road was the real trigger
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- ABS fault in the EBCM (usually a wheel speed sensor or its wiring) that disables rough-road calculation
- Genuine misfire from plugs, plug wires, coils or injectors while the rough-road data is invalid
- Damaged or dirty wheel speed sensor tone ring giving erratic wheel speeds
- Misfire flagged while driving on a very rough surface with ABS data unavailable
- Internal EBCM (ABS module) fault
- PCM software needing an update
Diagnosis step by step
Read codes from the PCM and the ABS module
A basic reader only sees engine codes; use a scan tool that can also read the EBCM. Write down the misfire code(s) and any ABS codes; ABS faults are the usual reason the rough-road data is invalid.
Tools: OBD-II scanner
Fix the ABS fault first
Repair the ABS code according to its own diagnosis, often a wheel speed sensor or broken wiring near a wheel. Passive sensors on these vehicles typically measure somewhere around 1,000–2,500 Ω; compare with the service specification for your model. Once the EBCM is fault-free it will resume sending rough-road data.
Tools: Multimeter, OBD-II scanner
Check wheel speed sensors in live data
Drive slowly in a straight line and watch all four wheel speeds on the scan tool. They should match within about 1–2 mph; a wheel dropping out or jumping points to the sensor, tone ring or its connector.
Tools: OBD-II scanner
Diagnose the misfire itself
Look at misfire counters per cylinder and the freeze frame (rpm, load, road speed). A misfire on one cylinder calls for plug, wire and coil checks and an injector test; a misfire recorded only at speed on rough roads suggests the rough-road filter was the missing piece.
Tools: OBD-II scanner, Spark plug socket
Clear and road test
Clear both modules' codes, then drive over mixed road surfaces. If P1380 returns without any ABS fault, check the EBCM's power and ground and ask whether a PCM or EBCM software update applies.
Tools: OBD-II scanner
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Replace a wheel speed sensor | Yes | $80–$350 |
| Repair wheel speed sensor wiring or connector | No | $80–$250 |
| Spark plugs, wires or coil for the misfire | Yes | $100–$450 |
| Replace or rebuild the EBCM (ABS module) | No | $350–$1,100 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Emissions / smog test impact
Will fail
With P1380 and the accompanying misfire code, the check engine light is on, which means a fail at US OBD emissions inspections until both are repaired.
Frequently asked questions
Why does an engine code involve the ABS?
The ABS module sees each wheel's speed and can tell when the car is bouncing over a rough road. The PCM uses that information to ignore false misfires caused by drivetrain shake. P1380 says the information wasn't available when it was needed.
Is my engine really misfiring?
Maybe. P1380 only sets alongside a misfire detection, so check the misfire counters and spark components. If none show a problem and the ABS had a fault, the misfire reading may have been caused by the road.
Will fixing the ABS clear P1380?
It removes the reason the rough-road data was missing. You still need to confirm there is no real misfire, then clear the codes and road test.
How is P1380 different from P1381?
With P1380, the PCM is still talking to the ABS module but the data it gets is marked invalid. With P1381, there's no communication with the ABS module at all, which points to wiring or module power instead.
Sources
- Manufacturer public service information (cross-checked)
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