SLK250 braking issue

[RayRutt]

The partner has a SLK250 that’s a 2015 with 9k on the clock. It’s thrown up some lights on the dashboard (ESP and Traction) and after having it plugged in some random codes that are on the image below. Now alarmingly it brakes fine under speed but when going real slow it’s got a scratching felling that can be felt through the brake pedal....any ideas?

 

[mikez328]

The partner has a SLK250 that’s a 2015 with 9k on the clock. It’s thrown up some lights on the dashboard (ESP and Traction) and after having it plugged in some random codes that are on the image below. Now alarmingly it brakes fine under speed but when going real slow it’s got a scratching felling that can be felt through the brake pedal....any ideas?

Probably one of the front wheel speed sensors. My 2012 SLK250 has gone through two (right hand followed by left hand 2 years later). The obvious pointers are that any of the electronics that require a wheel speed calculation will not work! ABS, TPS, Cruise Control and the brake HOLD features will be inactive. Do buy the OEM sensor for approx £40 - I tried a £15 version that did not work.... Dead easy to change but getting to the connection behind the inner wheel arch liner is a pain in th °°°°! Have a look on the MB SLK Forum for a DIY guide.

Mike

 

[Bellow]

Before digging into hardware, any tyre changes or wrong tyre pressures can cause this. If the lights on the dash aren't on all the time but occasionally and unexpectedly, then one of the safety systems is kicking in as it detects a non-event from misinformation. What you are feeling through the brakes will be the ABS thinking there's a wheel locking up and intervening to prevent that. Check tyres first.

 

[mikez328]

Before digging into hardware, any tyre changes or wrong tyre pressures can cause this. If the lights on the dash aren't on all the time but occasionally and unexpectedly, then one of the safety systems is kicking in as it detects a non-event from misinformation. What you are feeling through the brakes will be the ABS thinking there's a wheel locking up and intervening to prevent that. Check tyres first.

Yes, when a wheel speed sensor has failed the brakes will judder at low speed, just as if the ABS has kicked in - very disconcerting. Also, as soon as the engine is started the dashboard lights up like a Christmas tree with error warnings for ESP,ABS, TPS etc & they will not go out, An iCarsoft i980 code reader for £100 is a good buy as it will tell you which wheel the sensor has failed on & enable you to cancel down the dash error codes after changing the unit. MB dealers will quote/charge you about £500+ to change a £40 sensor for less than 30 mins work - a nice little earner.... Both left & right front sensors are identical. The part number is A 1725400017. Only buy the "ATE" branded sensor - this is MB OEM & WILL work.

Mike

 

[RayRutt]

1725400017

Probably one of the front wheel speed sensors. My 2012 SLK250 has gone through two (right hand followed by left hand 2 years later). The obvious pointers are that any of the electronics that require a wheel speed calculation will not work! ABS, TPS, Cruise Control and the brake HOLD features will be inactive. Do buy the OEM sensor for approx £40 - I tried a £15 version that did not work.... Dead easy to change but getting to the connection behind the inner wheel arch liner is a pain in th °°°°! Have a look on the MB SLK Forum for a DIY guide.

Mike

thanks for the reply

 

[RayRutt]

Yes, when a wheel speed sensor has failed the brakes will judder at low speed, just as if the ABS has kicked in - very disconcerting. Also, as soon as the engine is started the dashboard lights up like a Christmas tree with error warnings for ESP,ABS, TPS etc & they will not go out, An iCarsoft i980 code reader for £100 is a good buy as it will tell you which wheel the sensor has failed on & enable you to cancel down the dash error codes after changing the unit. MB dealers will quote/charge you about £500+ to change a £40 sensor for less than 30 mins work - a nice little earner.... Both left & right front sensors are identical. The part number is A 1725400017. Only buy the "ATE" branded sensor - this is MB OEM & WILL work.

Mike

Thanks for the reply....just a case of finding some in stock that I can collect tomorrow!