P06B4Sensor Power Supply B Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Despite the similar name, 'sensor power supply' is not the 5 V sensor reference (P0641 ff). It is documented in GM hybrid drive motor control modules: a 15 V supply that excites the motor position sensor (resolver) and powers the gate drivers of the inverter transistors, kept separate from the 5 V reference and the 12 V supply. In GM's 2008 Two-Mode hybrid, A and B are the two motor control modules. P06B4 means supply B, in the second motor control module, is too low: GM's 2008 Two-Mode hybrid flags below 12.0 V for 365 ms after two trips. Blown fuses, shorts in supplied components or an internal fault are typical. Mitsubishi's 2022 Outlander lists it as a sub-code.
- What you may notice
- Check engine or hybrid warning light
- Electric drive or hybrid mode limited or disabled
- Further motor position or inverter codes
- Likely causes
- LikelyBlown supply fuse
- PossibleSupplied component or wire shorted to ground
- PossibleInternal supply circuit faulty
- RareLow 12 V system voltage
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.