'lurch' when braking transfers from hybrid system to traditional brakes

[SimonB Sheff]

Has anyone had an issue when decelerating with the switch from the hybrid energy regeneration braking system to traditional brake pad braking?

I’ve been getting a ‘lurch’ at about 10mph, which is when the hybrid system stops, and the anti-slip warning light comes on amber for a few seconds.

It started sporadically and then became more constant.

And now the VSC, ABS and brake light warning light have come on amber, which according to the guide book means the hybrid braking system is no longer operational, but the car is safe to drive as the ‘traditional’ brake pads system is still working.

The Toyota main dealer replaced a cable to the ABS in the OSF wheel but the problem has recurred.

Any ideas what it could be?

 

A brief history:

Dealership replaced a bearing in OSF wheel before I acquired the car six weeks ago.

The anti slip light came on amber a couple of times and a couple of hours later I realised I had a flat on the OSF so I assumed the two were related.

I had the tyre replaced but anti-slip light came on amber from time to time, so I assumed I had a worn brake pad.

Anti-slip light kept coming on sporadically. Then when decelerating there was ‘slip’ or ‘lurch’ sensation between the ceasing of hybrid energy regeneration braking and traditional brakes taking over (when speed had dropped to about 10mph). VSC, ABS and brake light warning light came on amber.

Took car to Toyota main dealer. They said cable linking the ABS to the hybrid system had come loose and been worn through by rubbing against the tyre.

They replaced the cable and gave me the car back.

When braking the 10mph ‘lurch’ and anti-slip light flashing amber started almost immediately. 10 miles down the road, the VSC, ABS and brake light warning light came on amber. The 10mph ‘lurch’ stopped but braking was fine. So I’m guessing the brake pads are fine and the issue is something to do with the switch from hybrid to traditional braking.

[QuantumFireball]

That light is related to ABS, traction control and stability control, and since it only appeared after replacing the wheel bearing I'd imagine it's something to do with the ABS sensor on that hub which has still not been resolved. The sensor could have been fouled or damaged during the bearing replacement, they seem to be quite fragile.

Checking for fault codes may reveal the specific problem.

This seems to describe a similar situation (ABS sensor was damaged during bearing replacement): https://priuschat.com/threads/the-great-speed-sensor-mystery.139958/

[SimonB Sheff]

Aaron, thank you for replying and the link to the other thread.

 

Got the car back to Toyota and they found that, as you suggest, the ABS sensor wasn't sitting on the hub properly - a bit of corrosion had affected where it sat. They cleaned it up and it all works fine.