Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
The ML300 blue efficiency is...
The ML300 blue efficiency is hard to start especially when warm, it takes 3-4 goes before it fires, when you put your foot down nothing happens, the heater plug light stays on for 2-3 minutes after the engine has started. Now the ABS lights are on as well The car has only done 29,000 kms and has not been driven hard
The quickest route to repair is to have the car plugged into a diagnostic machine which will read off the fault code stored in the ECU (providing the light is still on at this point) and indicate which sensor has failed or whether the fault is more serious.
However with ABS systems 99% of the time its a problem with one of the wheel speed sensors and I'd first check the connections at all four corners first for any signs of corrosion or chafed wiring.
The sensor is located in the wheel hub so you'll have to remove each wheel in turn to inspect them all.
Also check that the toothed wheel that the sensor points to is clean and free of any debris.
you can check each sensor's function by plugging the two output wires into an AC voltmeter and spinning the wheel quite quickly, you should get a voltage signal that increases with rev's.
Its possible that the fault is only a bad connection to one of the wheel sensors.
This may be remedied by removing each wheel in turn and unplugging each sensor and cleaning the contacts with a squirt of electrical contact cleaner. Then refitting.
Matt thats great a good explanation,however its the hard starting that concerns me and the complete lack of power when you put your foot down, it used to jump up and go but now will only pick up very gradually.
If it is stationary and in park it revs's freely and no black smoke.
when you turn the key in the morning it will start before it cuts out, if you do the same when its warm it will only start on the 3d attempt