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When using the kickdown on the accelerator pedal a CEL is immediately generated and car is in limp mode until cleared.
Codes under stability management are one that says. One or more signals from the control unit combustion engine via CAN bus is implausible
Another code which relates to steering angle calibration needing to be done.
Another one is low pressure fuel circuit sensor is implausible. It has a new fuel pump. This sensor in question is on the filter side. Is it really bad or does some calibration need to be done with the scanner?
And also have a reman alternator installed in 2023. All lights pulse randomly when the vehicle is running. Voltage is correct but guessing this reman is no good. Lifetime warranty, but the voltage regulator is usually what causes pulsing.
Does anyone know what sensor is located on the back left cylinder head just above the crankshaft position sensor? Believe the O-ring has perished.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
First, get a Mercedes-specific scanner and scan all the controllers for codes. Then note if they are current or stored. Erase them and see which ones return. Come back here and tell us what you found.
Alrighty well found the problem with the limp mode. Anytime you use the kickdown it would throw the ESP light and go into limp mode. It finally threw a code for the accelerator pedal.
Which alternator did you buy? Mine looks old and filthy so i'm keeping my eyes open for a replacement. Plus I get the red battery warning on the dash when i start driving if I havent used the car in two days. Light goes away if i stop and restart the car.
It came from O'Rielly, brand was Ultima. The voltage regulator failed in just over a year. Unit was installed in about June of last year. Lifetime warranty covered it, but still unfortunate to change so soon. The new one works perfectly. I'm guessing it was just a defective unit and they honored the warranty without any hesitation.
At this point. Pretty sure they are all about the same. If you can get a Bosch go for it. That being said, having a lifetime warranty locally is nice.
254000 the signal for the pressure sensor of the low pressure fuel circuit is implausible. Code returned even after replacing the fuel pressure sensor on the filter hat.
Vehicle has a new fuel pump but original filter. Fuel pressure test shows 7.4Bar with the car off and utilizing the pump test. At rest the pressure holds at 4.45Bar.
Car runs great so it doesn't seem like the fuel filter is clogged at all.
U11600 a bus keep awake unit was detected. That one is new. This is for the ESL. Got an issue where the key plastic is worn out and unless you force it a bit to the left the ESL doesn't lock. Wiggle the key and it locks. New key is on order.
0155 the coolant thermostat has an electrical fault or open circuit. Already checked the connections and the thermostat has been replaced.
Also had a misfire code for cylinder 3
Changed the coil and that seems to be resolved.
That is a very productive chassis you've got here!!
We could really help your with more than code numbers and a complete picture of what troubles your chassis is delivering.
Launch "creader MB elite" ....cheaaaap!
MB Rule No1:
ensure you've got good voltage available - Use a "float charger" to prevent wasting batteries
Last edited by CaliBenzDriver; 08-27-2024 at 12:18 AM.
Alright. New pedal in and all codes gone except for one.
P2540. I've got a new Hella fuel pump assembly and a new low pressure sensor installed and still getting this stored and current code.
The fuel filter is original around 133,000 miles
Pressures at idle and revving is around 4.7BAR well within the 3-6 range.
I don't want to change the filter if I don't need to but after reviewing how the system works I'm guessing the issue is the siphon pump aka the filter is not matching what it should be due to being dirty. Does this theory make sense or is there something else.
Yes, seems your low-voltage pressure sensor is picking up electrical noise by traveling with pump power lines.
At some point consider separating wire runs out of harness bundle. I forgot if pressure sensor goes to a nearby module or simply R-SAM like the 2x tank float sensors.
According to that circuit, check cleanliness where sensor sources Pwr/GND. This may be introducing surge current that skew data as noted by fault.
If you have a scope that's when you get to visualize dirty signal.
The question is where does signal noise gets in?
My answer is to eliminate all room for chaos: harness cross-talk or marginal GND ?
Last edited by CaliBenzDriver; 08-31-2024 at 04:26 PM.
Vehicle starts perfectly fine. However when turning off to get out. You must turn the ignition slightly harder than you normally would to get the radio to turn off and ESL to lock indicating that there is play in the contacts of the turning portion of the EIS. Anyone know if this is an easy fix or even possible or does the unit need to be replaced? Again it works to start the vehicle.
Vehicle starts perfectly fine. However when turning off to get out. You must turn the ignition slightly harder than you normally would to get the radio to turn off and ESL to lock indicating that there is play in the contacts of the turning portion of the EIS. Anyone know if this is an easy fix or even possible or does the unit need to be replaced? Again it works to start the vehicle.
EIS is really an optical sensor that authorize F-SAM to power up the chassis plus the starter coil to crank.
Normally none of the modules should be repaired but it can be experimentally attempted given your skill set.
EIS and nearby SCM are both very rewarding targets to fix solderless pins + silicone grease + conformal coating. These modules may improve poor tranny shifts by reducing networking delays.
Last edited by CaliBenzDriver; 09-05-2024 at 04:02 PM.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by olebenz
Vehicle starts perfectly fine. However when turning off to get out. You must turn the ignition slightly harder than you normally would to get the radio to turn off and ESL to lock indicating that there is play in the contacts of the turning portion of the EIS. Anyone know if this is an easy fix or even possible or does the unit need to be replaced? Again it works to start the vehicle.
So, you insert your key to start the car? I always use the push button start/stop. But I know you can change the length of time the radio stays on until you open the driver's door. Not sure about the ESL engaging.
The key issue is simply play/wear in the EIS. It's very slight. Easy to work around.
The low fuel pressure code has also been resolved. Wound up replacing the pump and also the filter assembly. So far so good. Runs well. Back to back the idle is significantly smoother.
Well the thermostat code popped up again so either a wiring issue or a failed thermostat housing sensor/heater thing. it looked like it had recently been changed. I'll check the connector again.
The fuel pressure code came back again going to assume a false positive. Pressure is proper. I've read it could be an injector. The car sat for a bit so I'll drive it and see what happens. The fuel was gross coming out the old filter when changed
Well the pulsing voltage has returned. Maybe it never went fully away. Obviously with the headlights on its most noticeable. It seems to come and go and is totally independent from the RPM. Doesnt matter if you hold RPMs at 3,000 or idle. The pulsing is random but pretty consistent. Only being stable.for say 3-5 seconds at a time.
The alternator has already been replaced and the battery is new. It's totally possible the new alternator is bad again.
My question is. Is it possible to have pulsing if the battery current sensor is bad? If it's bad will it throw a code? I don't have any codes related to voltage.
Anything else besides the voltage regulator that would cause pulsing ?
As always thank you in advance for any assistance.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Are you getting your alternators from O'Reilly or some parts store chain? Remanufactured or new? My experience is that I've had a 33% failure rate within a year on "remanufactured" alternators on other cars I've owned.
I know it's a lot more expensive, but you should go with an OE or Genuine alternator. What year is your car? Below are my choices for my 2015 SL400. Yours might be less expensive. Also, the voltage regulator is separately replaceable.
It's possible that a Bosch replacement alternator and or a higher quality voltage regulator maybe a solution.
I've changed the alternator again with the lifetime warranty O'Reilly auto unit and this time it says remanufactured in Mexico and the voltage regulator says USA. It also has a different fan, coil, and pulley. The build quality appears superior. So this one is different than the last two which were made in China.
Found the dash lights were still slightly pulsing but didn't have time to take it for a drive yet. They were pulsing considerably less than with the last alternator. I put the battery on a trickle charger to make sure it's topped up which someone also suggested. It's showing 12.7v.
I've also replaced the main battery ground wire with sensor. No change.
Lastly in regards to what CaliBenz suggested about the FSCU. Turns out someone had been trying to sort this before I got the car as the FSCU had been replaced with another one. Found the unit had yellow paint writing on it which is common on used parts and not fully seated in position and the carpet was pulled back.
What I did find on the FSCU was green corrosion on one of the pins on the harness side. Cleaned it up with a stainless brush and cleaner.
Hopefully this resolves the problem.
Then I'll have to sort the thermostat code. The thermostat was already replaced but still throwing a code. Checked the connector at the thermostat and it's clean.
08-17-2024, 09:46 AM
