P2C43Battery Isolation/Voltage Stabilization Control Circuit
- Generic OBD-II code · Powertrain
- Can trigger limp mode
- How the car detects it
- Some vehicles split their 12 V system with a switch so that a heavy starter load, typically an automatic restart, cannot pull the supply of control units and displays down. A Ford patent on start-stop cars puts that dip at roughly 5 to 7 V without such separation. The switch, a relay or semiconductor isolator, is commanded by a control module, and P2C43 is the general fault of this command line, usually an open circuit or a driver that sees no plausible load. No manufacturer documents P2C43 publicly; the only published case in this family is Ford's PowerBoost F-150 with an auxiliary battery isolator, which stores the performance code P2C44. Low, high and intermittent faults have their own codes P2C45 to P2C47. Expect auto stop-start or electric assist to be held back and a fault lamp; driving normally remains possible.
- What you may notice
- Warning lamp or powertrain fault indicator on
- Automatic stop-start no longer stops the engine
- Radio or displays may reboot during engine starts
- Likely causes
- LikelyOpen control wire or loose connector at the isolator
- PossibleIsolator relay coil or electronic switch failed
- PossiblePoor ground connection of the isolator circuit
- RareOutput driver in the control module defective
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.