355 F40 brakes question

When you say it has F40 brakes, I assume just the rotors and pads were replaced and it still has the F355 Teves ABS? What are you using to scan the system? Do you know if the ABS computer has been modified in any way? If it has, maybe the scan tool can't pick up the faults as it normally would.

Since both warning lights are on, it may help (a little) to isolate the problem. I believe ABS faults put both lights on, but brake faults won't unless one of the pressure or fluid level sensors has failed (I believe some of the sensors feed both systems).

Here's the wiring diagram for the Teves system:

F355 Teves ABS System

The pink ("S") wiring illuminates the brake warning light. If you follow the pink wiring to the fluid and pressure sensors, you will see that some of the pressure and level sensors have have dotted lines going to dual switches (i.e. one pressure or fluid sensor controls two switches). One switch will feed the ABS computer, the other will feed the brake light circuit. I assume you've checked fluid levels already.

It probably won't be a brake wear sensor issue, because the brake wear sensors only talk to the brake light fault circuit, not the ABS circuit.
There might be a dirty or faulty wheel speed sensor. You could try cleaning the sensors and checking the wiring for damage.

Without knowing what has been modified on the car, we can really only guess at what's going on.

 

You should have the Teve’s system, if only the rotors and calipers replaced with F40 parts. The Accumulator and green valve/switch going bad is my first guess based on experience with the Teves system. Scan tool probably having a read error. All very presumptive, but I chased problem on my 1996.

Search my user name and brakes for my procedure. I replaced accumulator with Jag bulb and green “switch/valve” with Buick Reatta piece I believe. All sourced on Amazon. Cleared my lights right up. Easy.

Hope that helps.


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