ASR light on on the dash - Drives fine

I made a very sharp turn around on a street, and my ASR light came on. Drove the Sprinter another 150 miles to get home (no issues at all from the drivers perspective). Once I stopped the engine, and restarted, the ASR light is off until I drive again for a block or 2.

-- 2002 Sprinter --

I used the DAD to check for errors and got the following:

C1200 - Possible Brake Light Switch failure.

C1104 - Left Front Wheel Speed Sensor - Check for .6 to 1.8 K ohms.

C1105 - Right Front Wheel Speed Sensor - Check for .6 to 1.8 K ohms.

My Brakes Lights appear to be working fine, so I doubt its the switch (I may change it anyway, since its only $18 and moderately easy to get to). Pumping the brakes while stopped does not cause the ASR light to go on, but driving does.
I suspect maybe a bad connection at where ever the front wheel Speed Sensors plug in.

I traced back where these appear to go from where they attach to the front wheel hubs. The wires appear to get taped into the larger wiring harness that gets directed under the drivers seat. From there, it looks like the run thru a channel up under the floor towards the front of the van. The wires from the sensors look and feel fine (nothing appears damaged there).

I stopped looking at this point and decided to ask if anyone knows where these eventually plug into anything. Its hard to measure the resistance of a sensor if you can't find a place to check them with a meter. The 2003 Service manual suggests cleaning the contacts as part of the diagnostics for this error.

No other dash warning lights come on (well, my glow plug lights usually stay on all the time and have done so since I owned it, so I doubt its related).

The 2003 Service manual (118865-va-chassis_sgmldiag.pdf - page 50) implies that these eventually plug into a CAB wiring harness connector on the side of the ABS controller - that might be, but if so, it sure takes a round-about-way of getting there, since the pump is closer the wiring before it gets routed into the cab of the Sprinter. I will see if I can clean that ABS CAB Harness Connector with contact spray.

I searched to see if anyone else has done this on the forum, but did not find anything to help me figure out where the sensor wires eventually connect to.

If anyone has ever replaced one of the Front Wheel Speed Sensors, they will probably know where the cable for this gets routed. Any insight would be appreciated.

Log the fault code info into your notebook, erase them and see what returns after the ASR light returns.

Then call me on my Sprinter Hot Line. 412-366-6165.

Doktor A

Cleaning the ABS CAB Connector contacts appear to have fixed the problem.

I would still like to know where the Front Speed Sensor wires end up connecting to. I don't need to change anything, but I might need to some day.

I use Spray Contact Cleaner (CRC Brand) that I found at an auto parts store. Many problems on my Sprinter have been dirty connections.

Sliding the connector cover off (pull up) is almost easy, except that the Turbo hose assembly is in the way (but if you take your time and pull/wiggle gently you can get it out - you'll have the same task putting it back).

The Lever on the CAB connector has a ratchet that once you lift it, will slide out a lower clamp. It needs to open fully.

When the lever was open all the way, I pulled up, separated the connector and sprayed both parts of the CAB connector, let it sit for a minute and then re-assembled.

The connector cover took a bit of force to get re-snapped back on. It probably would have been easier to do this with the drivers side head light removed (USA vehicle), but there is enough room there if you take your time.

I took it for a drive to refuel and I am not having any issues now.

The 2003 Service Manual shows what the connector wires to - I reproduced it here.

jmoller99 said:

Cleaning the ABS CAB Connector contacts appear to have fixed the problem.

I would still like to know where the Front Speed Sensor wires end up connecting to. I don't need to change anything, but I might need to some day.

I use Spray Contact Cleaner (CRC Brand) that I found at an auto parts store. Many problems on my Sprinter have been dirty connections.

Sliding the connector cover off (pull up) is almost easy, except that the Turbo hose assembly is in the way (but if you take your time and pull/wiggle gently you can get it out - you'll have the same task putting it back).

The Lever on the CAB connector has a ratchet that once you lift it, will slide out a lower clamp. It needs to open fully.

When the lever was open all the way, I pulled up, separated the connector and sprayed both parts of the CAB connector, let it sit for a minute and then re-assembled.

The connector cover took a bit of force to get re-snapped back on. It probably would have been easier to do this with the drivers side head light removed (USA vehicle), but there is enough room there if you take your time.

I took it for a drive to refuel and I am not having any issues now.

The 2003 Service Manual shows what the connector wires to - I reproduced it here.

Click to expand...

Thanks for the pics and the abs wiring diagram I am going to try this contact cleaning