djdyal

I bought the car used last year. Starting in June of 2017 we had intermittent issues with starting the car. Pushing the start button (while stepping on the brake) would result in the dash lights illuminating but nothing else would happen. Typically, we would turn the car off, get out, shut the door, lock the car, unlock, and try again. It varied how many times it would take before the car would start. The dealer decided it was a bad battery and replaced it (the battery was two months old). This did not correct the problem. Subsequently, we went back to the dealer. This time, they determined that the cam sensor was bad and was keeping the car from starting. All of the sensors were replaced for $1,600. The day after we got the car back, it once again failed to start. Back to the dealer again. This time, the dealer determined there was a bad relay in the starter motor. The dealer, to its credit, replaced the starter with no charge to me. The day after this was complete, it would not start again.

Doing research, it appears this is a common problem, but I don't see a consistent solution. I have seen the cam sensor as the problem, the ignition button, bad keyfob, the ignition system, the starter, the alternator and so forth. It appears to me the dealer can't find a problem without having a code. So, unless an error code is generated, they are lost.

By the way, the service technician has seen the non-start problem for himself since they kept the car for almost a week.

Has anyone had a similar issue and had it resolved?

Thanks in advance.

TuLsaViPeR

When was the last time the Alternator was replaced? I had similiar issues not quite the same but similiar issues. turned out it was my alternator was not properly supplyinbg power to all of my systems. Once I replaced the alternator all of my system issues were fixed. (car wouldnt start, Heater would come on Randomly, Lights would come on but I couldnt turn them off, Doors wouldnt lock or unlock, Dash board would light up and turn off)

I never even received a check engine light. I just did a bunch or random research. I actually replaced the alternator myself. Also I have a 2013 G-Wagon so its not the same car but some of the issues sound like what I was having.

Also did you pull any codes? Do you have a code reader? The engine has a lot of sensors. You should also ckec some of your fuses, souds like one of your fuses might be going out.

djdyal

To my knowledge, the alternator is original. The dealer got the codes, and the first time they said it was the cam sensor, second time a fault in the starter. Me getting codes or doing my own repairs would be like brain surgery. There is a Youtube video made by a repair shop which discusses this issue of dash lights but no initiation of the start-up. He focuses on the fuses.

TuLsaViPeR

1st off your Alternator is way overdue for getting replaced. An alternator usually last 4 to 5 yrs. I would either get yours rebuilt or order a new one and then have the old one rebuilt and sell it online. It beats the $20 core charge that the parts supply gives you. 2nd get a code reader yourself

2nd check the fuses.

To be honest I got a code reader and I started messing around with my truck, and it's kinda fun.

Have you ever watched any of those auto repair shows on TV? I'm convinced most of the people working on our cars, don't know what the flickkkkkk they are doing?

mercup

I would consider a 4-5 years MTBF for an alternator to be premature. 7-8 years would be closer to what I would consider to be typical alternator lifetime...so you are in that range.

A quick and dirty test for potential alternator failure is to check battery voltage prior to starting, then check the voltage while the engine is running...especially with every possible electrical component on. If the voltage while running exceeds the battery voltage by a volt or 2 you it is probably in good shape. Typical voltage while running is going to be 14 volts or so.

Some OBDII readers well give you live voltage readings. Also the Carly app and reader will give you live voltage readings as well...you could watch the voltage during these transient issues. and that might tell you something.

TuLsaViPeR

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My Alternator went out after 5 yrs... You're wrong!!!

mercup

You obviously do not understand modes of failure for vehicle components...you seem to think if yours failed at 5 years everyone's will fail at 5 years which is most certainly not the case. Alternator lifetime is highly effected by usage patterns, temperature, humidity and more...so your extrapolation of potential failure date is flawed since your local experience has no real impact on global failure rate and timing.

djdyal

So, the car started ok for awhile after the new starter motor was installed. Then it went right back to the same old problem. I did check the codes myself. The principal code indicated a problem with the can shaft censors. Since these had already been replaced, research indicates it could be the wiring harness with a short. So, back to the dealer again. This time, they have decided to replace the main computer module, again at their expense. I now have about $6,000 in repairs to fix the non-starting issue. So far, it has now started for three straight days.

djdyal

rudywaller

Djdyal, I know it's been a while but having the same issue with my 2011 gl550. Was the SAM module the final end-all fix? I'm in desperate need for a fix.

Thanks

alxdoher

djdyal, Just checking if the SAM module was the front or the back?. Having the same issue with my 2012 GL550.

Thanks!

alxdoher

Rudywaller, Just checking if the SAM module was the problem in your case also.
Having the same issue with my 2012 GL550.

​​​​​​​Thanks!

rudywaller

I had to replace the ignition switch which meant re-keying the electronic keys. Total $1,500.

But, one other thing I learned is I was using the key to insert into the ignition. Well there is a replacement ignition button that will go into the keyhole and work just like any newer button ignition system.
I think it was around $89 and you just plug it in your self. So if you're using the key to insert now, then get this and it will save you a lot of money.

​​​​​​​Good Luck