SRE
Senior Member
I dropped the SL500 (R230) off for it's MOT the other day. At lunch time I got a call from the garage saying that they had got in it to take it into the testing bay and it wouldn't start. The car had been running fine and always starts immediately so wasn't sure what the problem could be but grabbed the spare key and headed over. Sure enough, everything worked exactly as it should have until you switch on the ignition and then you receive ABS and ESP "Display Malfunction" fault warnings. Turning the key does nothing and the starter doesn't even attempt to spin. Same thing happened with the spare key (including in keyless mode) and after a few attempts we also noticed that the cooling fan was coming on and running at full blast. The garage tried plugging in their diagnostic machine but couldn't get it to communicate with the car (Its not STAR as they are not a Mercedes specialist - I was only taking it for an MOT).
The car is stuck in Park and I remembered something about faulty brake light switches causing this to happen so I checked with a friend who confirmed that the brake light switch would produce the ABS and ESP faults so returned to the garage armed with a new switch, confident in the belief that this would be a 5 minute fix and I would eventually get it MOT'd. Unfortunately, swapping out the switch made no difference and the car is still sitting on their forecourt, locked in Park!
The voltage on both batteries is ok and I did wonder about the Gear Selector not registering that it is in Park but pushing it hard to the right produces a "Put selector in Park" warning on the dash which disappears when you release it. The Garage has tried more than one Diagnostic machine on the OBD port but none have managed to talk to the Merc.
I am at a loss as what to do next. There is of course the very slight chance that the new brake light switch was faulty but even then, I doubt that would explain the fan or the diagnostic port problems. Having recently moved to the area, I have yet to find a local Mercedes specialist but it looks like I will need to find one fast. Then I just have to solve the problem of getting it there!
Any suggestions will be gratefully received.
The car is stuck in Park and I remembered something about faulty brake light switches causing this to happen so I checked with a friend who confirmed that the brake light switch would produce the ABS and ESP faults so returned to the garage armed with a new switch, confident in the belief that this would be a 5 minute fix and I would eventually get it MOT'd. Unfortunately, swapping out the switch made no difference and the car is still sitting on their forecourt, locked in Park!
The voltage on both batteries is ok and I did wonder about the Gear Selector not registering that it is in Park but pushing it hard to the right produces a "Put selector in Park" warning on the dash which disappears when you release it. The Garage has tried more than one Diagnostic machine on the OBD port but none have managed to talk to the Merc.
I am at a loss as what to do next. There is of course the very slight chance that the new brake light switch was faulty but even then, I doubt that would explain the fan or the diagnostic port problems. Having recently moved to the area, I have yet to find a local Mercedes specialist but it looks like I will need to find one fast. Then I just have to solve the problem of getting it there!
Any suggestions will be gratefully received.