P0E43: Hybrid/EV Powertrain Control Module B
Do not keep driving
The car may drive on one axle with reduced power. Have it read by a shop with a tool that can talk to this module directly — a basic code reader will show only this one code, which is not enough to work with. Ask about a software update before agreeing to a replacement module.
What this code means
A fault has been recorded in the second hybrid powertrain control module.
A second hybrid controller means the car has more than one thing to control, and in practice that means two drive motors — one per axle — or a drivetrain elaborate enough that one processor cannot manage it in the time available. Torque has to be apportioned between machines many times a second, and that is a job usually split rather than centralised.
Which makes the designator load-bearing. A fault in module B is a fault in the half of the drivetrain it governs, so the car will very often still move — on one axle, with reduced power and no all-wheel drive. That is mild enough to drive home on and is not a reason to.
This is the P0700 pattern again, and the same warning applies: it is a pointer rather than a diagnosis. The detailed fault lives in that module's own memory, and reaching it needs a tool that can address the module directly. A basic reader will show this code and nothing behind it, which is how a vague code becomes an expensive guess.
Before condemning the module, rule out the two cheap causes — software that is out of date, and a module fitted or reprogrammed without being configured for this vehicle, which fails its own checks for an entirely sensible reason.
Likely causes
Start here
- Failed control module · specialist
- Corrupted module software · moderate
- Corroded or loose connector · specialist
Less common
- Incorrect module configuration after replacement · specialist
- Failed power or earth supply to the module · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0E43.