Is200 Abs And Trc Warning Light Fault Solution.

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Symptoms - TRC warning light flashing with ABS light constantly on. Loss of ABS and Traction Control. All other system operating. No recent work or non genuine parts on vehicle. In original trim with less than 80k , 2003 SE Model. Well serviced and looked after.

Diagnosis - Confirmed ABS loss and TRC. Systems have shut down.

- Checked all fuses. All good.

-Put vehicle on ramps. Visual check no obvious damage.

-Accessed OBD manually using workshop manual instructions. Abs light flashed 41 then 46 repeatedly. TRC flashed code 43.



Code 1246 = Master Cylinder Pressure Sensor Malfunction


Code 1243 = Malfunction in ABS control system

-Cleared codes and disconnected Battery. On ignition warning lights apppeared. Fault therefore must be detected at check and not a rolling fault.

-Mulled it over for the day and read some of the manual. Unusual failure, seemed like the next step would be test the ABS control unit.

-Went shopping (she made me) noticed for the umpteenth time people were trying to weld themselves to the back of the bumper and in the week or so the warning lights appeared a few horns I couldn't understand. Wonder if I have brake lights?

-checked brake lights. Inoperative.

-checked fuses, bulbs and any wiring, checked power to bulb - no power. Pondered.

-check brake pedal switch - Inoperative!! Disconnected plug and bridged contacts. Brake lights on. Cycled ignition. Warning lights off. Without bridge warning lights on.

-Took out switch, cleaned contacts and dried off some maintenance spray (potentially caused my own problem..dohh) Benched tested and working. Re installed in car allowing for 80k wear.

- ABS and TRC functioning.

Conclusion. If ABS and TRC only warning lights appear. Check brake light in operation and pedal switch is working. Have yet to road test ABS/TRC function. When it rains I will!

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Thank you for taking the time and trouble of making such a comprehensive and detailed post,this will I'm sure help many members in the future.

Also congratulations on repairing the switch rather than replacing it.

Long gone are the days when a simple stop light switch resulting just in having no brake lights!

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Big thanks to the Forum too, I found the codes and PDF of the workshop instructions to access the OBD. I did post occasionally but can't find any of my old posts to add too.

Have since last post, written it off repaired it (cosmetic bumper) and some other adventures! After 8 months off the road and with a fresh Battery fired up first time. Still putting a smile on my face.

Still can't decide if defaulting the ABS and TRC off is a good idea. But then it would have only been a matter of time before someone wrote off the back bumber without the brake lights...!

Other useful info might be.... the only recall is for the drivers side carpet clip. Really is a danger! didn't hook it back properly and stuck the pedal at WOT.

A knock from the suspension that befuddled everyone turned out the be the internals of the shock letting go. No change in performance. Took ages to figure

Edit move as you like Mr Steve :-)

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Digging up an old post here but:

How do you access codes using OBD without a scanner? I don't have the workshop manual

Secondly, my ABS light is on and TRC is flashing. All brake lights are fine and all ABS sensors are okay. Any other ideas of the problem? 

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