Have a 2002 A4 Quattro 3.0 with the dreaded ABS and ESC light on. I have changed the brake switch and cleaned the drivers passenger abs sensor and checked the wiring from sensor. Vag com states its malfunction drivers side sensor. I know the abs modules fail so I have found some oem on eBay. My question is what numbers from the module need to match and do they have to be exact? Do the numbers from the pump that the module came from have to match also?

Thanks

Brad

 

Did you verify which ABS sensor might be bad? A scan tool that can read C codes (chassis codes) can tell you which of the four sensors are bad, if one of them is. I would be sure it's not a sensor before buying a new module or rebuilding yours.

Also, I've seen on the B5 S4, brake dust and road crap can accumulate in the ABS tone ring and make it hard for the sensor to read the castellations in the ring. That's worth looking at too.

 

Per VCDS

00283-ABS Wheel speed sensor, front left (G47)
30-00-open or short to plus

 

There's your answer. If the wires aren't broken and the connector pins aren't corroded, you need a new sensor.

 

Okay so try sensor first? OEM or aftermarket? If so which aftermarket?And if it still gives me same code after sensor then abs module?

 

Make sure the wiring isn't broken and the connector isn't corroded, like I said. If not, but a sensor from ECS or FCPEuro - they'll work fine.

 

Thanks

 

 

I never thought that the brake light switch would be involved, but since changing it (noticed that the brake lights didn't come on without feeling resistance from the master cylinder) there has been no more ABS EPC lights on.