Skid control ecu or ABS actuator?

[fjtuba]

Sorry to add another ABS VSC question, but I just want to see if anyone else has had the exact same issue I am having. Some other posts have been similar, but not exactly the same.

My ABS and both VSC lights pop on occasionally after I have been driving a while.
When they do come on, it is always as I am braking to stop at a light, etc. They never stay on constantly. In fact, they usually go out again as I am braking to a stop later. The brakes are functioning great. Strong and smooth. The lights are intermittent.
My code reader shows codes C1223 (abs fault) and C1246 (Brake MC pressure sensor malfunction).

My mechanic says he thinks it must be the Skid control ecu because he can't find anything wrong. The factory manual mentions the ABS actuator as a possible problem also.

Help?

Anyone had this same issue with a solution. That ecu is mucho $.

Thanks for any help anyone can provide.

 

[fjtuba]

Could this be related to the main junction box TSB replacement? The upgrade was never done on my LC.

 

[100 TD]

As soon as it happens, put it into neutral and listen carefully, listen for the brake booster pump running. When driving normally, it takes a couple of applications of the brake pedal to lower the pressure in the accumulator enough for the pump to come on to boost it back up. This should only take about 3 to 5 seconds IIRC. If your pump is running longer than this time, it is probably overcharging, and you will here it running.
If it is doing this then something is telling the pump to run, even though it is up to pressure, either the pressure switch is U/S, or, and most likely, the ABS circuit is telling the pump to run continuously.
I believe this can happen when a little bit of moisture tracks down cables and causes a short across pins in an electrical connector. Mine does this about once a year in the rainy season, to fix it (I haven't found the offending electrical connector yet), I pull the ABS connector from the master cylinder. This allows the brakes to work properly, but disables the ABS. If I had VSC or TRAC I expect these would also be disabled. I run the aircon flatout on recirc with heat on full for a couple of days to remove as much moisture from the cab as possible. The fault clears and I plug the ABS connector back in.

Please do not disable your ABS. Please seek professional advice.

I am about to get a new windscreen fitted so I will be looking very carefully when it is removed to see if I can find a leak, could also be my roof rack bolts.

 

[spey2tay]

I had the same problem and codes. It baffled me until a hard failure. The pump went out. Not sure if the pressure sensor code is related to how long the pump had to run to make up pressure, I know some aircraft systems work that way. When I took the pump apart the brushes had vaporized. Yours might just be dying a slow death. Maybe one of the sharp LC mechanics could verify all or any of what I am saying. I replaced the pump, and the problem disappeared. Of course the engine light came on after that with some vacuum leak code or something like that and it took me a few months to get the correct part for that.
Prepare to take out a second on your house to pay for that pump, if ithas failed. In excess of $2000.00. Maybe your problem will be something like a leak on one of the hydraulic lines and all you have to do is tighten the end up for free.

Good luck,
I wish I could be more specific about things, but I have had too many baked potatoes in aluminum foil, and it happened years ago. I do remember the price, and those codes. It only took 4 days between throwing out the codes and complete failure.
Russ

 

[CANEX]

Sorry to add another ABS VSC question, but I just want to see if anyone else has had the exact same issue I am having. Some other posts have been similar, but not exactly the same.

My ABS and both VSC lights pop on occasionally after I have been driving a while.
When they do come on, it is always as I am braking to stop at a light, etc. They never stay on constantly. In fact, they usually go out again as I am braking to a stop later. The brakes are functioning great. Strong and smooth. The lights are intermittent.
My code reader shows codes C1223 (abs fault) and C1246 (Brake MC pressure sensor malfunction).

My mechanic says he thinks it must be the Skid control ecu because he can't find anything wrong. The factory manual mentions the ABS actuator as a possible problem also.

Help?

Anyone had this same issue with a solution. That ecu is mucho $.

Thanks for any help anyone can provide.

Did you manage to get this fixed as I have got exactly the same codes??

Cheers Chris