Mercedes-Benz Forum banner

ABS-ASR-BRAKE PAD-BARKE, LIGHTS ON W140 S420 1996

2K views 20 replies 6 participants last post by  scottpeterd 
#1 ·
Original symptoms, Check Engine light came on (car ran fine) I got a OBD1 code reader (led flashing light) and Read the codes.
All were minor codes on pins #20-21-23 All cleared fine.
Problem, after cleared codes, started car and ABS-ASR-BRAKE PAD-BRAKE Lights came on and still had CEL on. Drove car (1/4 mile) and found out it was in LIMP MODE also. I checked all fuses and did reset procedure for ABS by lock to lock on steering wheel. No change. Rechecked codes and found that my LED light would come on faintly on Pin#6 (ABS-ASR CONTROL MODULE N30/1) at (.881v) and would light the LED light at Pin#10 (TCM N15/1) at (4.6mv) What should I do next 1. Disconnect battery? HELP
 
#4 ·
OBDI was accessed from the 38 pin connector in the engine compartment - but only through the 1995 model year. OBDII started in model year 1996 (on V8s) with a 16 pin connector under the steering wheel. The 38 pin connector in the engine compartment remained for other code reading. What is the 10th digit of your VIN? S specifies a 1995 model, T a 1996 model.
 
#8 · (Edited)
I'd check the insulation between the speed sensor cables and the brake pad sensor cables. Those two cables are packed together and there is a possibility to have some poor insulation when stressed/aged and the leaked current causes your type of problem. Use a multimeter/ohm meter to check the resistance between them.
 
#18 ·
For 1996- it has to be a Star system or clone which means either dealer, MB shop, borrow or buy a clone. There's a nice long thread on Star clones in the 129 forum. I think it's hard to justify a purchase if you have just one car and occasion problem. They are not just costly but also very time consuming.

But keep checking your OBDII codes - see what comes back after you delete. Write down the code number and google it. There could be a clue in the OBDII codes.
 
#21 ·
I was also baffled why my engine lost power randomly. Turned out to be the wires running to the EGR vacuum valve on the left side of the intake manifold. The plastic connector had disintegrated from the heat, and the wires were shorting. Removed power from one of the LH modules. But DID NOT throw any lights. That turned out to be another problem (plugs inserted upside down in the pod).

Living here in Africa, and having too many fuse failures over the years, I equip all my cars with thermal 15A auto-reset breakers (available from Amazon). Just make pigtails with 1/4" male spade terminals to plug into the fuse sockets. And they are polarized, so that has to be taken into account. These go into critical circuits that will otherwise stop the car from running.

https://www.amazon.com/gp/product/B00DNHAC5A/ref=oh_aui_search_detailpage?ie=UTF8&psc=1


After having this problem with my S600, I made a small board with 4 of these breakers, and a small harness. Then if I have a short again, I just pull over, wait a minute, then I'm on the road again.

May not be the most elegant solution, but I don't have the luxury of waiting for a tow truck on a safe road.

Cheers
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top