Data Erroneous from Engine Control Module
The ECM (Engine Control Module) is reporting data that doesn't make sense based on its internal parameters.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine control module is getting readings (like temperature or pressure) that don’t match what's actually happening, indicating a potential sensor failure or bad data.
What the computer is actually seeing
The ECM receives sensor data (like for temperature or pressure) that is outside of acceptable ranges, triggering a fault due to conflicting inputs or sensor failure.
What a healthy reading looks like
For sensors, check voltage outputs around 0.5V to 4.5V; temperatures should match expected operating ranges (e.g., coolant 180-220°F, oil around 220°F; pressures depending on the sensor).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check basic wiring and connectors related to the ECM and sensors. Look for corrosion or damage. If damaged, repair or replace the wiring/connector.
- 22. Using a scanner, review live data and confirm which specific data is erratic or wrong. If uncertain, go in-depth with individual sensor data readings.
- 33. Check for any other codes. If there are related codes (like SPN 5390 or SPN 5392), investigate those first, as they may lead to the root cause.
- 44. Test individual sensors related to the ECM for correct operation (temperature and pressure sensors). Consult service manual for expected values and resistance checks.
- 55. If all sensors check out, then consider reprogramming or replacing the ECM, but only after confirming all sensors and wiring are good. This step is expensive and should only be the last resort.
Common causes
- Faulty sensor
- Wiring issues
- Poor electrical connections
- Faulty ECM
- Incorrectly functioning modules
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with SPN 5391 active?
Moderately safe, but the symptoms can vary. It's recommended to address the issue soon to prevent further damage.
Will this code come back after clearing it?
Yes, if the underlying issue isn’t fixed—either a faulty sensor or wiring problem—it will reappear.
Why does this code sometimes pair with SPN 5390?
SPN 5390 indicates a similar underlying issue, typically related to erroneous data from different sensors. It’s essential to address both codes together.
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