Pin16

U0123

Lost Communication With Yaw Rate Sensor Module

Severity
Critical
Driving
Drive only to a garage

The control module has stopped receiving messages from the yaw rate sensor module. On most vehicles the ordinary hydraulic brakes are unaffected and the car still stops, but anti-lock braking, stability control and traction control depend on this module and will be switched off. Braking hard on a wet or loose surface can now lock a wheel, and the car will not correct a slide for you.

Possible causes

What you might notice

What to check, in order

  1. Drive gently and allow much more stopping distance than usual until this is repaired. Nothing about the pedal will feel different, which is exactly why it catches people out on the first hard stop.
  2. Check battery voltage and state of charge before anything else. A weak or failing battery drops modules off the bus and sets lost-communication codes with no wiring fault at all - this is the single most common false lead in this whole family.
  3. Check whether this code is current or historic. Lost-communication codes are routinely set by a flat battery, a jump start or a battery disconnection, and a historic code straight after one of those events usually records the event rather than a fault.
  4. Check the fuses and earth points for the yaw rate sensor module. ABS modules draw heavily and their earths corrode.
  5. Note how many U-codes are stored. Several at once points at battery, earth or bus wiring, not at several modules failing simultaneously.
  6. Inspect the module connector for corrosion and water. ABS modules are usually mounted low in the engine bay where water collects.
  7. Do not condemn the module until power, earth, bus wiring and battery condition have all been eliminated.

Read this code from your own car

Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.

Get Pin16 on Google Play

Where this code sits