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While driving the ESP light came on and car went into limp mode. When I got it home I checked for faults with car running and without motor on. I have attached a list of faults. When I went to restart the car, it would no longer turn over. Put both batteries on charger overnight but still no go. Not sure if I have an ignition issue or tps sensor or throttle clogged. Maybe even pedal sensor. I am not familiar enough with faults to know if tps can stop enging from starting causing the ignition code? Anyone suggest a starting point?
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
How old are your batteries? Not sure if charging both at the same time is a good idea. Just because you have charged both batteries does not mean they held a charge. The codes indicate an electrical problem. However, the gas pedal does fail on these cars, are easy to replace, and not terribly expensive on-line.
What did you use to scan your car? Can you clear codes?
I used Autel maxi200 to read codes. I did cleR them but still get TPS and ignition faults. Both batteries were replaced in 2020 and hold a charge. I do t think batteries are the issue. Need to figure out next few steps.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by Socratic101
I used Autel maxi200 to read codes. I did cleR them but still get TPS and ignition faults. Both batteries were replaced in 2020 and hold a charge. I do t think batteries are the issue. Need to figure out next few steps.
Yeah, probably not the batteries. But could still be the gas pedal. When my pedal went bad, I lost all throttle control (not fun on a highway and you are in the wrong lane to pull over). But restarting the car temporarily fixed it.
The TPS wouldn't cause this unless the readings are way out of whack. If the car thinks one of the tires is flat, it may disable the ESP and put the car into limp. But, not turning over is something else. Are you using your key in the key slot to try to start or just using the push-button start? What happens?
Yeah, probably not the batteries. But could still be the gas pedal. When my pedal went bad, I lost all throttle control (not fun on a highway and you are in the wrong lane to pull over). But restarting the car temporarily fixed it.
The TPS wouldn't cause this unless the readings are way out of whack. If the car thinks one of the tires is flat, it may disable the ESP and put the car into limp. But, not turning over is something else. Are you using your key in the key slot to try to start or just using the push-button start? What happens?
Tried both the key and push button on shifter. Also checked to be sure shifter was locked in park. Also tried retraining steering position sensor (turn wheel right and left). Removed one battery terminal from each battery and reconnected. Could try unplugging battery control unit for 5 minutes next. The car did sit for about 10 days without use and I did get a low battery warning. Put trickle charger on and battery came up okay but maybe that caused some protection or ? Something maybe needs to be reset? Just not familiar with issues on this car - so if I sound a bit unknowledgeable.....I guess I am.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
These cars are very temperamental when it comes to electrical stuff. Sitting for 10 days could cause a drain on the electrical consumers (trunk) battery to the point of temporarily disabling all electrical controls. I would check electrical connections to the throttle body, just to rule out mice chewing through wires. This video may also help.
Yes, dash light come on as normal. Trans is ok. I actually gave up and had the car towed to my mechanic. He is not an MB specialist but thought he might be able to isolate what is going on. He is thinking a ground somewhere. I'll check back in here with an update of what, if anything he finds.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by Socratic101
... I actually gave up and had the car towed to my mechanic. He is not an MB specialist ...
Good luck, then. How much does he know about Mercedes? This does not sound like a grounding problem since all of the current faults point to the throttle actuator (which is the throttle body). You may have a failed throttle body.
And battery problems ALSO . Is the rear battery to MB spec? AGM? Your fault list has nothing to do with ground, if you had ground issues your diagnostic would likely catch it.
Have a thorough diagnostic done with MB star Xentry and remove the mystery.
I hear you. Mechanic let me know that if he couldn't fix it he wouldn't charge me. We'll see. Do you know if faulty throttle position sensor will not allow motor to crank?
I don’t know the answer to your question but I will repeat, have the car scanned with MB Star Xentry, then you will know without guessing. Do not throw parts darts.
Looks like ECU is shorting according the mechanic. Was able to narrow it down after some time troubleshooting. ECU kept blowing fuse when isolated. Anyone know a reliable vendor for testing and repairing the unit? Mechanic was going to do a search.
Love to get multiple opinions but I don't own a tow truck to drag the car around town! Guess I just have to bite the bullet and hope it turns out okay.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by Socratic101
I used Autel maxi200 to read codes. I did cleR them but still get TPS and ignition faults. Both batteries were replaced in 2020 and hold a charge. I do t think batteries are the issue. Need to figure out next few steps.
Do you mean the Autel MaxiAP AP200? While that may be ok for a $50 OBD dongle, it's not the same as a $650 Autel MaxiDAS scanner or an Xentry diagnostic system.
None of your codes say there is a short or grounding problem. They point to the throttle actuator (body) and low voltage. If a component has an open or short circuit, there will be an error code saying so.
Probably just a result of time and heat. Apparently the location of the ecu (on top of engine) is not optimum. There is some indication that this is an issue with this car but I don't know how common.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by Socratic101
Probably just a result of time and heat. Apparently the location of the ecu (on top of engine) is not optimum. There is some indication that this is an issue with this car but I don't know how common.
It looks like more than just time and heat. It would have to get VERY hot to melt solder on a circuit board, like at least 361°F. Doubtful if it gets that hot even on top of the engine. It looks like something shorted out. I only mention this because it may happen again.
I hear you. I dont what caused the short that fried the Board. According to mechanic, other than blown fuse they did not find any faults that would have caused it.
09-23-2023, 11:09 AM
