P058ABattery Monitor Module Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The battery monitor module (intelligent battery sensor) sits on the negative terminal of the 12 V battery: a shunt measures current, electronics also measure voltage and temperature and calculate state of charge, health and cranking ability, reporting over LIN. Energy management uses the data for alternator control, idle boost and stop-start release, which is why the engine module diagnoses it. GM sets P058A–P058F in its engine modules from 2016 as type B, warning lamp after two trips. P058A means the module reports an internal fault of its own over LIN. GM checks it every 250 ms above 9 V, without LIN faults and at outside temperatures of −20 to 50 °C. Battery data are then unreliable – stop-start is blocked and the alternator usually runs a fixed substitute voltage. Loss of communication is a separate U code.
- What you may notice
- Check engine light on
- Stop-start not available
- No driveability problems
- Likely causes
- LikelyBattery sensor faulty internally
- PossiblePoor supply or ground at the sensor (loose terminal, corroded connector)
- PossibleSensor not relearned after battery replacement or disconnection
- RareModule or engine module software
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €60 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.