ABS Sensor in Seat? - PeachParts Mercedes-Benz Forum

Rahulio1989300E · #1 01-23-2011, 06:42 PM

Today I removed the front right seat to clean the carpets thoroughly and grease the seat rails.

There were a total of 3 connectors for the seat, two black multi-pin ones and a two wire red connector. (Both the seat end and the car end of the connector were red.)

I had to pick something up from a store and I noticed that the ABS light on the dash is always on now, unless I switch to ignition position 0 or have the key out. (Seat is still uninstalled.)

Do the front seats interface with the ABS system some how? Something to do with SRS (Supplemental Restraint System)?

1989 300E

compu_85 · #2 01-23-2011, 06:53 PM

If the seatbelt buckle isn't hooked up it will trip the SRS light.

-J

daddi · #3 01-23-2011, 07:47 PM

I think you have a brake down.

Rahulio1989300E · #4 01-23-2011, 09:01 PM

Well the seat is still out of the car, the only dash light that is on is the yellow ABS light. The SRS light functions as it comes on before the car starts, just like every other light in the cluster, but it never comes on during driving.

I will be re-installing my seat tomorrow, so it will probably go away, just seems strange that the ABS system is linked to the passenger seat in some way.

compu_85 · #5 01-23-2011, 09:04 PM

I can't think of any ABS connections that are under that seat. I believe the rear wheel speed sensor has a connection under the rear seat.

-J

ILUVMILS · #6 01-24-2011, 12:10 PM

Maybe the bulbs/connectors are swapped in the cluster.

Rahulio1989300E · #7 01-24-2011, 03:38 PM

Quote:

Originally Posted by ILUVMILS

Maybe the bulbs/connectors are swapped in the cluster.

Hmm, you may be on to something here.

If I jumped the red connector, and complete the circuit, would that make the light turn off without causing issues or damaging anything? I may be installing seats from a newer MB as a project soon.

Rahulio1989300E · #8 01-24-2011, 11:26 PM

Alright, the carpet under the seat was NASTY!

After vacuuming and cleaning with carpet cleaner, it is much cleaner underneath the reinstalled seat.

Old seat is back in and connected, ABS light (actually the SRS light) is now off.

I looks like I did accidentally switch bulb locations for the SRS and ABS dash lights. Will need to correct that soon.

compu_85 · #9 01-24-2011, 11:35 PM

I'd refer to the wiring diagrams before just jumpering the seatbelt buckle. Plus I'd think you need to use the one original to the car anyway so the seatbelt still works.

Does your car have dual airbags?

-J

Rahulio1989300E · #10 01-25-2011, 02:21 AM

Single airbag, for driver only.
The reason I asked about the SRS connector jumper is because of a possible seat swap...

I have the front two seats and rear base and rear backrest pieces from the interior of a wrecked 2005 E55 AMG. I was thinking about swapping in the front two seats from the E55 into the 300E.

While the 300E passenger seat was out, I test fitted the E55 seat. It will fit, but will need a custom bracket to be fabricated in order for it to bolt up.

The 300E seat has 5 motors.
1. Seat forward and backward movement
2. Rear of seat up and down movement
3. Front of seat up and down movement
4. Backrest forward and backward
5. Headrest up and down movement.

The E55 seat appears to have the exact same configuration. (5 motors, same usage)

Right now I am trying to sort through the wiring diagrams for both seats. I want to get the existing seat adjustment switches in the 300E to function with the E55 seat's motors.

If I can bypass all of the electronics in the E55 seat and just tap into the positive and ground connections of each motor, then I should be able to get a fully adjustable E55 seat in the 300E. I will loose the memory function on the driver's side, but considering the huge upgrade in comfort... I could care less...

Also, should the car be sold in the future, I can completely undo this modification and replace the stock seats as there should be no modifications done to the 300E's connectors or switches.

I may have to remove the seatbelt buckle from the old 300E seat and somehow adapt it to the E55 seat so that I can use the connector from the 300E seatbelt buckle to plug into the SRS harness to prevent the SRS system from lighting up the dash.

compu_85 · #11 01-25-2011, 11:10 AM

More then just keeping the SRS happy, you also have to be sure the old seatbelt buckle will latch into the new seat's latch. Just test the old seatbelt buckle with an ohm meter, that will let you know if you can just jumper the connection.

Keep in mind that the computer looks at the seatbelt switch to determine the threshold for firing the airbag, ~7mph without the seatbelt buckled, ~14mph with. If the seatbelt is not buckled it will not fire the tensioner.

-J