Diagnostic check wrong

[greendollar45]

Hi ,

Car , BMW 318i , failed it's MOT due to the ABS lights orange on dash so booked a diagnostic check at local garage (quoted £26) , went along and was sent to another garage as that one didn't have the correct equipment .....all good so far , went straight into the other garage , test done in 5 mins which showed both front ABS sensors faulty .

Asked price to fix , and was quoted £88+ vat each for the sensors NOT fitted , declined as I'd looked online and knew I could source them much cheaper ( 2 phone calls and got them for £28 each) .

Asked them how much they wanted for the diagnostic test expecting it to be around the £30 mark only to be stung for £60 .

Pretty peed off but ,hey thats garages for you .

Anyway , replaced sensors myself , easy job , one hex bolt and unplug and the sensors off , took a couple of hours tops with tea breaks .

But surprise ,surprise the ABS lights are still on .

Now I have to fork out for another diagnostic check , can I demand money back from the garage as they have supplied me with a wrong diagnostic check ?

[Conniff]

Just because the lights still on doesn't mean that the diagnostic is wrong, those cheap sensors could be the reason or the setting up at the wheel, or the wiring.

[greendollar45]

Just because the lights still on doesn't mean that the diagnostic is wrong, those cheap sensors could be the reason or the setting up at the wheel, or the wiring.

 

What are you saying , the carparts dealer is in the business of selling parts that don't actually work ? and the garage informed me that it was the sensors not the wiring . As for setting up at the wheel , replacing a sensor wasn't exactly rocket science .

[Conniff]

Even the most costly of things can be faulty on receipt. If the wire is open circuit then there will be no response from the sensor, there is no check to see if it's the wire or the sensor that is faulty, it just returns a 'sensor faulty'.

[CrappoMan]

...But surprise ,surprise the ABS lights are still on .

Now I have to fork out for another diagnostic check , can I demand money back from the garage as they have supplied me with a wrong diagnostic check ?

 

The ABS light will stay on until it is reset using the diagnostic equipment, but will come back on if it senses a fault.

 

It is quite rightly showing that an error has occurred sometime in the past. It needs resetting AFTER the sensor is fixed/replaced.

[Conniff]

That is so obvious that I assumed it had been done.

[CrappoMan]

He doesn't say if the garage tried resetting the fault, just that they did the test, i.e: read the error code from the ECU which said ABS sensors faulty.

 

If they did reset the error code, it would have come straight back on, as the sensors were still faulty.

 

Now that he has fixed the sensors, he wants to clear the error code, which means a trip to the dealers for an appointment with the diagnostic machine.

[greendollar45]

He doesn't say if the garage tried resetting the fault, just that they did the test, i.e: read the error code from the ECU which said ABS sensors faulty.

 

If they did reset the error code, it would have come straight back on, as the sensors were still faulty.

 

Now that he has fixed the sensors, he wants to clear the error code, which means a trip to the dealers for an appointment with the diagnostic machine.

 

aahh , I see , so I'm gonna get stung for another £60 unless I can find another garage that'll do a diagnostic check and reset the error code a bit cheaper ( pretty sure that I read that these things check then reset themselves everytime the ignition is turned on ) . Many thanks .

[greendollar45]

That is so obvious that I assumed it had been done.

 

Not to me

[heliosuk]

Another bunch of amateurs and pub mechanics me thinks. Conniff is right with what he says.

 

The problem here is, as usual, people relying on the diagnostic system and how it works. If the ECU registers a sensor fault it can be a number of problems.

A. A faulty sensor,

B. Faulty wiring

C. A fault in the ecu sensor circuit.

D. A fault in the component the sensor is looking for.

 

The system does not need re-setting if the repair has been carried out correctly. It works on the number of failures over a period of time.

 

There are two generally used systems, a serated wheel/hub and a magnetic ring. Failure of either of these items will show a sensor fault and you can change as many sensors as you like, it will still be there.

 

BMW from memory favour the serated wheel on the hub so give that a good clean if you can get to it.

 

Can't see how you can get any money back here as it seems to be a case of the blind leading the blind.