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ABS Computer Repair Help

470 Views 16 Replies 4 Participants Last post by  mrboca
Can anyone recommend a company that can repair the ABS Control Computer on a 1999 E300?

Part number: 003-431-30-12

I've replaced all four speed sensors and front hubs and the system still fails.


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When I had a similar problem some years back, I had my car scanned by an Indy shop. Results were not very helpful! Described here. I did my own search and I think it was the P1401 code that suggested it could be the ABS pump. Here is a post I made back then:

If you think it could be ABS pump, there is something you might try.

What goes wrong with the pump, is that the brushes in the pump motor wear down and no longer make proper contact. An electrical motor repair shop might be able to repair a pump. It is no big deal.

Each time you start the car, the computer checks to see if the ABS system is working. To do this it tries to run the pump. If pump doesn't run. you get the ABS and other lights.

I found that I could get the pump to run by tapping it with a rubber mallet or something like that. Best to do it while someone turns key on and keep doing it for a minute or two. You may hear the pump run. In fact you should listen to see if pump runs first. If it does, problem is likely elsewhere.

Regarding code readers, I don't think any OBD2 meters will read the relevant codes. You need to have a Star type system. Even then, the codes will be cryptic, because there are a number of inter-related systems which affect each other. However, if it is a wheel sensor, I think you get a specific code.

When I had similar lights, I did following:
  • changed brake light switch (made no difference)
  • Had codes read by Indy. He had no clue, but I had him give me the codes.
  • With codes, searched internet including here!
  • Finally found some stuff on ABS pump brushes.
  • Bought used pump and installed.

No lights since! And ABS does work.
There is more in that thread: Dreaded ABS BAS light

Also in this thread: BAS, ASR, ABS Lights on, w/C1401 code

Funnily enough, we went out to a dinner last Friday. Roads were slippery. I twice had to brake hard. Both times the ABS worked as it should. The chattering is always a bit of a surprise when it does!

That $50 eBay used pump bought 10+ years ago has worked out well for me :)
C1401 is the circuit fault for the ABS pump. The monitoring of the ABS pump is done by the Traction module. If this code comes up it is clearly the ABS pump. However, if no faults while the car is not moving, and warning lights coming on when the car moves, sounds like something else.
In my case, it was the pump itself. (Or more specifically, the pump motor brushes). But it could also be the pump's wiring or the pump relay (easy to check)
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