Prius 2nd gen Traction Control light comes up when braking at lower speeds.

serox_21

Hello,

I have a 2007 Prius 2nd gen that developed a problem with traction control

When braking at slow speed just before car comes to a stop(speed still between 15-5Km/h) traction control lights up(blinking) and for a split second is like brakes gets disconnected.

When braking at high speed everything goes well until vehicle speed gets into that 15-5Km/h band.

If slowly braking when approaching a stop and lift the foot of the brake pedal (when around 15Km/h) and press slowly again the traction control issue is not manifesting.

Does anyone know a service in Dublin that's specialized on Prius sensors/electric problems ?

On my last annual service at Toyota dealer(annual oil change and overall check), there were no error codes and the issue was not present(at least they havent noticed it) .

They were asking 150€/hour just for diagnostic if I wanted they to investigate.

I'm not really willing to pay a fortune for a diagnostic which for sure will be more that 1h.

serox_21

Another update:

While driving on M1, three lights came up in the dashboard that won't turn off.

VCS, ABC and (!) are always on now. The good news is that the brakes still work and traction control issue above doesn't show up.

I think this is a bigger problem and currently none of the brake assistance services are working. Only standard braking available, but car stays on the driveway until fixed.

Still looking for a service that are specialized on hybrids car.

serox_21

Car is fixed.

I'm writing here what the cause and the fix is for future reference in case anyone has a similar problem.

I went to a local service for a error codes scan: 30€. I was prepared for the worse, a abs pump failure, but I was lucky.

Error codes:

C1235 - Foreign Object is Attached on the tip of Front Speed Sensor. Right Hand side.

Went home and in the evening I removed the front wheels to inspected abs sensors. Wires looked ok. Then I removed the sensor on front right side wheel(the one indicated by the error code). On the the sensor there was small flakes of rust, covering the tip of the sensor. Cleaned the sensor, inserted it back, then moved to inspect the left side. Left side was clean.

Mounted sensors back and put on the wheals,then started the car expecting lights are gone from the dash.

Started the car, but lights were still there. Without a way to clear the codes I was expecting the lights to stay on.

Took the car for a ride and after 200 meters dash lights went off.

Brakes are working perfectly and the issue from the title is gone too.

It seems that over time bits of rust got stuck on the abs sensor(which has a small magnet on the tip), triggering traction control issues and ending with abs failure.

I really have been lucky with just a 30 min DIY job in the end.

Atlantic Dawn

Thanks for sharing the fix, glad you got it sorted. 👍️