P2DCBStarter/Generator Phase X-Y-Z Current Sensor Correlation
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2DCB compares the three current sensors of the starter/generator's X-Y-Z phase group with one another or with the DC side. In a star-connected winding the instantaneous phase currents must add up to roughly zero; if they do not, at least one sensor is wrong, even though each may sit inside its own limits. Mazda's bulletin 01-004-25 shows that an integrated starter generator can carry a second stator driver group called X, Y and Z beside U, V and W. GM's eAssist instead balances currents: if the value derived from the phase sensors differs from DC-DC converter plus battery pack current by more than 40 A in at least 90 out of 96 checks, one every 2.08 ms, P0BFD sets as Type B and current control runs without sensors within 187.2 ms. No manufacturer documents P2DCB publicly. Single-sensor faults: P2DC1 to P2DC6.
- What you may notice
- Check engine light with hybrid or 48 V system warning
- Reduced electric boost and recuperation in substitute mode
- Start-stop may be disabled
- Likely causes
- LikelyGain or zero drift of one phase current sensor
- PossibleDisturbed supply or reference voltage shared by the sensors
- RareCalibration or software fault in the starter/generator controller
- 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: €150 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.