U0159: Lost Communication With Parking Assist Control Module A
What to do
Reverse as though the car has no parking sensors, because for now it has none you can hear.
That is the whole point of this page. A warning light that fails is obvious — you notice it did not come on. A warning beep that fails leaves nothing behind, so you carry on relying on a sound that is never going to arrive.
Use your mirrors and look over your shoulder. If you have a reversing camera, do not treat it as a substitute — it shows what is directly behind the bumper and tells you nothing about the post beside your rear wing.
Two things worth mentioning to a garage. Has the bumper ever been off, or the car been resprayed? The sensors and their wiring live in the bumper, and a bumper refitted with the loom trapped or a plug not reconnected is one of the commonest causes.
And if you tow, unplug the trailer and see whether the fault clears — many cars change how the parking sensors work when a trailer is connected, and a corroded towing socket can confuse that completely.
The car is otherwise entirely safe to drive.
What this code means
The parking assist module has stopped being heard from. The general reasoning is at U0100, and module B is at U0243.
The safety content here is the one from U0160, and it applies with full force because parking sensors are almost entirely an audible system.
A warning lamp that fails is noticed the moment it should have lit. A warning sound that fails leaves nothing behind at all — no symbol, no marker, no evidence. So a driver goes on reversing on the beeps, and the beeps are never coming.
The instruction is therefore specific: reverse and manoeuvre as though the vehicle has no sensors. Mirrors and a look over the shoulder. A camera image, if the vehicle has one, is not a substitute — it shows what is behind the vehicle at bumper height and nothing about the bollard beside the rear wing.
Where the fault usually is has a useful shape. A single failed sensor normally reports itself — the system stays alive and tells you which one. A silent module means the whole system, and the causes are supply, connector or harness rather than a sensor.
Two of them are worth naming because they follow ordinary events. Bumper work — the sensors and their harness live in it, and a bumper refitted with the loom trapped or unplugged is common. And repainting, since paint over a sensor face changes what it hears; that usually produces sensor-specific faults rather than this one, but a respray is a marker for the bumper having been off.
On a towing vehicle, unplug the trailer and see whether the code changes. Many vehicles suppress or reconfigure parking assist with a trailer connected, and a faulty socket confuses that.
Likely causes
Start here
- Corroded or loose connector · easy
- Damaged wiring harness · moderate
- Physical damage from road debris · moderate
- Water ingress into the module connector · moderate
Less common
- Blown fuse or failed supply · easy
- Damaged data bus wiring · moderate
Symptoms
Components involved
Information, not instruction
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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
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