Rx400H Traction Control Light When Slowing To A Stop

[Roybus]

When braking gently to a stop sometimes when I get to below 5mph, I get the feeling like engine braking suddenly disappears so the car seems to stop slowing down at the same rate so you have to push the brake pedal a little harder to stop. Imagine in a manual, you kept your foot off the clutch as you braked to begin with and then, with your foot still on the brake, you quickly pushed the clutch down fully. At the same time, the traction control warning light briefly flashes on. I'm certain that the wheels aren't actually losing any traction whatsoever when this happens.

This happens more often when coming to a stop down a hill, but it doesn't by any means happen every time - maybe only 1 time in 5 or 10.

Any ideas what's happening?

[RXJasonRX]

Hello I'm not sure ,but I think what you are referring to is the change between normal breaking and friction breaking or something like that, there is a thread somewhere I think in the forum about when the 400 changes from one method of breaking to the other there is a slight Sensation somewhat like what you've described, but maybe I am on the wrong track . Have you actually got the gear selection in the b mode for engine braking?

Sent from my Nexus 7 using Tapatalk

[Roybus]

I'll search "friction braking" - thanks.

This is in normal D mode.

[Gliderpilot]

If you have the car in "D" then there is no "engine" braking but from normal road speed there is regerative braking (charging the battery) first then friction braking takes over to bring you to a final stop. At the transition there is a sensation that the brakes are not as effective so you tend to press harder on the pedal. If you watch the power meter when braking 9in a safe area of course) you can see it moves into the blue section when you first apply the brakes and then moves out of it when the friction brakes take over. Hope this helps!

[Roybus]

Thanks Gliderpilot - it's exactly as you describe. Is the fact that it sometimes feels like it "lets go" as it changes from one kind of braking to another (and the TCS warning lamp comes on) something that needs looking at though?

[Gliderpilot]

I think the TCS warning light could be that you have an ABS/TCS wheel speed sensor on the way out! Get someone to check it out on the computer.

[rayaans]

Make sure you're tyres aren't nearing 3mm or less too. When my RX450H was on 3mm at the front the traction control light would come on at every turn and stop

Eventually I changed tyres all round even though the rears had 4.5mm. The fronts were at 2.3mm at this point and it was getting borderline dangerous lol

[ChrisKaye]

Tyre and alignment issues can cause the lights to come on when braking or even going around roundabouts quickly...