mansur

Hi, I have G500 year 2002 and the BAS and ESP lights are on
I'm looking for a wiring diagram but have not been able to find one
If anybody has one or a link please post it or pm me
Or if i can get a service manual or a link to get one
the code I'm getting is C1401 high pressure pump relay not shutting off

please HELP

thanks in advance

bluescooter52

I am getting the same codes on my 2002 model. I will be watching for information. I have heard the the ECM/ECU on this model is an issue. Anybody else?

GLKMM

Guys just ask the maaaaan.... His name is MBRedux...

Martinwilson

so I have a high mileage 2002 G 500 which has developed ABS/Bas light. Was intermittent at first, now constant.Tried switching the brake light switch, resetting the steering sensor by turning the wheel all the way to the left and right multiple times, testing the ABS unit, checking the relay at the rear Sam module, and checking all the fuses. diagnostic code comes up as a C 1401, high pressure ABS pump malfunction. Previous codes had a random ABS wheel sensor, so I replace that. Now all the wheel sensors are sending data reliably during driving. Also had a random C 1100 code which indicated a bad connection of the electrical type. These two subsequent codes have not reappeared. Now, After resetting the C 1401 code, it will reappear after the car begins moving forward for a few seconds. Wondering if you might’ve figured out your problem. Suspicious about the rear Sam unit, but since it’s an expensive part, wanted to see what you found out.

Floobydust

I would not suspect the rear SAM itself right off the bat. The potpourri of error codes you have been getting makes me think that you need to check your electrical system's operating voltage with the engine is running. It should be around 13.8 volts. If your battery is old, that may be an issue too. The BAS/ABS systems in the early MBUSA Gs are notoriously sensitive to system voltage. The brushes on the pump itself can be a failure item as well. I haven't done it, but it should be possible to check for pump continuity/function independently from the system. I would check these items our first.

Martinwilson

Thanks for your reply, Flobydust. Did check the voltage—steady 14.2 running and did get a new battery in the last 3 months as the old one finally died. The abs issue predates the battery failure—but I see that the bad battery may have been affecting voltage for a while before it died. I removed and sent out the abs unit and it was tested and found to be error free but I don’t know that they specifically checked the motor/brushes. The variety of codes including c1401 were prior to the battery completely dying—now with the new battery in, only the 1401 reappears. I’ve tried tracking down all the harness connectors that could be a problem to see if corrosion could b an issue. The bas/etc unit under the passenger side carpet had pretty significant green corrosion on the connectors. Cleaned carefully and put silicon on before reconnecting. Opened that unit to look at board and visually it was ok Thought I had found my answer but... same error. Same code.

Floobydust

It seems like you covered most of the bases.

When you say ABS unit, I assume you mean the hydraulic unit under the hood. A proper check-out of that unit should have included checking out the pump to make sure the motor was good. 1401 reliably reappearing when the system does its-self check at 3 MPH really seems to point to a bad pump issue.

When you say that you have checked the relay on the SAM, how did you do that? Substitution with a know good one or ringing the existing one out with a power supply and DMM?

I'm not sure what you are using to pull codes with, but maybe it's time to find someone (indie, dealer) with a Star/SDS system to see if there are more in-depth error codes.

Martinwilson

Gotcha. I think you are right about an indie. I think I’m beyond my abilities. I bought a used hydraulic unit (identical part numbers from a same year clk and popped it in but without the star reprogramming/initialization couldn’t tell if it would solve the problem—abs light and adjacent “brake” warning—not happy. Put the original back in. As for solenoids, put in the adjacent identical solenoid and tried the whole routine again. Am I right that the new abs/hydraulic block would need to be initialized with star diagnostic system to tell if it would solve the problem? Is that a fairly normal thing to ask an indie shop to do. Haven’t found anyone great here, but this question may not require specific g wagon knowledge, is that correct?

Martinwilson

I tried to pull the pump motor off the hydraulic block but couldn’t figure it out. I wish I could pull my ABS electronic unit off the block assembly/pump assembly. and put it onto the CLK pump/block assembly. That would probably answer the question I guess since it would require initialization. Not sure if there is away to do that.

Floobydust

Yes, I believe it does require "adaptation" as the parameters from a CLK would be much different from a G (even though the G derives much of its gear from the C class).

Here is link for changing the ABS unit for a W203 (https://www.pelicanparts.com/techart...eplacement.htm) Not, sure, but it may give you some insight into how to swap them. The adaptation should stay with the module so if you can do it, a swap would be a good test.

Martinwilson

The update to this problem is that the truck spent 3 weeks at a well-regarded indie shop who used their star diagnostics to pull same codes c1401 and another front wheels speed sensor code. Replace wheels speed sensor. Same c1401. No abs unit available from MB dealer so sourced another used one. Initialized it. Still c1401. When 12 volts sent directly to pump works fine. Diagnostics suggested checking high pressure pump trigger relay. Tested relay and fine. At this point the shop started testing input/output from pins on BAS/ESP unit under passenger floor mat. Found good 12 volt power to unit but pin to ABS unit 8V (not 12V)— believes unit board has failed. Harness/pin connections cleaned. Recommended new BAS/ESP Bosch unit to be ordered from Germany $2200 + programming. Total with diagnostic wild goose chase $6 k. Yikes. Trying to see if there is a Bosch BAs/Esp module repair service that works on this unit. No luck so far.
part on module
463-545-14-32
bosch number
0 265 109 495
cant find correct used unit on eBay.
stuck. Would love any advice. Might have found the problem. Might have to bite the bullet and pay the 6 k. Part of course not returnable.