2002 ML320 Electrical Problems
 

Hello Everyone,

I've been a frequent reader, but I'm a first-time poster.

I am have several issues with what seems to be unrelated electrical systems. I'm hoping that someone can help point me in the right direction.

I'll start with a list of symptoms:

• rear o2 sensors not recognized
• all break lights come on occasionally
• ESP (orange triangle) will engage on dry asphalt
• driver door does not lock
• cruise control does not engage
• FM tuner does not work, but CD and AM work fine
• volume will change itself
• sometimes vehicle will stall and then go when try to begin accelerating
• EGR code has been thrown, but no mechanical diagnosis has found anything

My first thought is that it might be the AAM, but then I've been reading that there could be some ground issues. Perhaps a mixture of both?

I'm not an electriction, but I'm not afraid to try new things.

1. Has anyone else had these problems?
2. What types of tools do I need to diagnose?
3. If I have the tools, where should I start?

Thank you so much for your help!

The brake lights, ESP light and cruise control all have to do with the Brake Light Sw.

Remove the panel under the driver's instrument panel and access the brake light switch. First check to see that it is partially blue in color. The blue colored switch confirms that it was replaced per a recall.

Regardless if it is blue or not, remove the elec. connector and twist the switch clockwise and remove. Then follow the instructions in the pdf. Pull the pin out all the way, manually press down on the brake pedal and insert switch and lock in place. Then release the pedal and pull up on the brake pedal and connect the connector. Then see if any or all of the problems recur.

If you do not have a blue switch, go to a dealer and purchase the latest one, #001 545 95 09 and install the new one the same way as above.

https://mbworld.org/forums/m-class-w...ml#post5812567

https://mbworld.org/forums/m-class-w...ml#post5039586

I will try that and report back. Thanks!

This is a feature. Stops you locking yourself out by pressing the dashboard lock button with the door open, leaving the key in the ignition, and closing the door behind you.
So is this. Your ML may have an emergency call system that mutes your radio so the call centre operator can hear you. Sometimes the e-call module thinks you've crashed and starts calling.

If you don't have an owner's manual, you can download one.

UPDATE
 

It looks like my idle voltage is significantly lower than it should be. It is currently at 11.9.

I will be changing the alternator at this point as well.

I wish there was a way to disengage the e-call module. I have another option that I use.

There is......Read post #9. Buy the loop, install it, then remove the module & throw it away.

I have edited my post. I forgot the OP is still going to use the MCS.

Art,
Don't you also have to instal an FO bypass adapter and reprogram the FO ring assignments. I have been wanting to remove my telaid unit since I bought my ML500.

Mike

You certainly do and here is how to do it. M/B part #000 545 33 84 and cost approx. $5.

I should have mentioned for "Aftermarket systems".