SLK 200K error codes P0720 & P0500

[Andrew Keeler]

Can any one help please; I am getting error codes P0720 and P0500.
P0720 Output Speed Sensor Circuit Malfunction.
P0500 Vehicle Speed Sensor Malfunction.
My ABS/BAS warning light has also been on for a while.
I got the error codes from the AA and they recommended changing the Front ABS/Speed sensors, but on this forum I have read that it’s best to replace the Rear Left sensor. I have also seen that it could be the sensor on the gearbox, which is a garage job.

Can anyone give me some advice on this matter, and whets my best course apart from a service dealer?

 

[SL300-24]

I would start with a new brake light switch

 

[Terry_]

It sounds like you have a failed speed sensor.

 

[Benza750]

Go to a good independent with star diagnostics and they should be able to pin point the fault for you.
Guessing at it will more than likely cost more.
If it is wheel speed they will be able to tell you which sensor or pick up ring it is by checking the actual values & live data

 

[Terry_]

As above yes. But those fault codes relate to a Failed speed sensor. Which is a common fault on the R170

 

[Benza750]

Speed sensors are common on them, as is water into the connector especially into the rear sensor connectors where it comes through the floor pan.
We have replaced 2 drive shafts aswell this year for broken rings that have split through rust on the shaft & then come loose bringing up the same fault codes

 

[Terry_]

Speed sensors are common on them, as is water into the connector especially into the rear sensor connectors where it comes through the floor pan.
We have replaced 2 drive shafts aswell this year for broken rings that have split through rust on the shaft & then come loose bringing up the same fault codes

You don't need to fit driveshafts for broken reluctor rings
ABS Reluctor Rings
Saves the customer a few sheckles !!!

 

[Benza750]

You don't need to fit driveshafts for broken reluctor rings
ABS Reluctor Rings
Saves the customer a few sheckles !!!

We give all our customers options, some will choose just the rings & others opt to pay more.
Carnt work it out at times