91stealthes

Strangely, sometime during approximately 0.5 miles of easy soft sand driving the CEL light came on. I noticed it once we parked at our spot.

CEL still illuminated when leaving the beach. Another easy 0.5 miles back on soft sand with no issue. Returned home, rinsed the car and undercarriage and the car sat for 24+ hours. I then moved the car and CEL was still on. Another 48 hours have passed and CEL is no longer illuminated.

I figured I'd still pull codes to see if anything is stored, so I stopped at AutoZone. Seems like something may have went haywire while driving down the beach. Battery and Accessory Battery were replace less than 6-months ago. Brand new crate engine with new turbo replaced less than 10,000 miles ago. Also, I do not have ADS. Thank you for any support!

5025 - No CAN Message Was Received From Control Unit Engine Management
5126 - L 6/3 (Left Rear Speed Sensor) : Check Installation Position of Sensor
5106 - L 6/1 (Left Front Speed Sensor) : Check Installation Position of Sensor
5399 - CAN Signal 'Gear Selected' From Control Unit N15/3 (ETC [EGS] Control Unit) is Implausible
5420 - Fault Or Disturbance In CAN Message From Control Unit N15/3 (ETC [EGS] Control Unit)
5026 - No CAN Message Was Received From Control Unit Transmission Control
5539 - One Or More Signals Sent From Control Unit N51 (Airmatic With ADS Control Module) Via The CAN Bus Is Implausible)
6001 - The Supply Voltage Of The Control Unit Is Too Low (Undervoltage).
5173 - Steering Wheel Angle : Signal Fault
5116 - L6/2 (Right Front Speed Sensor) : Check Installation Position of Sensor

Also, P2BAD - NOx Exceedence - Root Cause Unknown Secondary DTC showed as well.

BlownV8

Looks like bad wheel speed sensors. Just replace them all with genuine MB parts. If you replace them with a cheap aftermarket ones, they will fail in a short time. Maybe someone else will chime in.

Max Blast

CEL is the p2bad code or the 5025

all of your wheel sensor and CAN bus codes may be from water intrusion, or sand fouling a wheel sensor, so can the 5025.

or a low battery event caused them all, by introducing water to either the battery compartment or into a ground.

just clear them and see what comes back.

if you gotta replace wheel speed sensors go OEM and do them in axle pairs.

and give it a good wash first.

chassis

Sand or saltwater in the wheel speed sensors.

How old is the battery on this vehicle?

91stealthes

Thank you for all the thoughts and suggestions guys!

I was thinking the same, maybe they were sitting in there before the beach too. Interestingly, I found a PDF document of codes on the forum that indicated codes 5126, 5106, and 5116 could be ignored. I would replace all 4 with OEM if needed.

Batteries were replaced less than 6-month ago, but I will check voltage. The battery bay is dry and no water was driven through, so no water intrusion. Sand on sensors definitely a possibility. Will replace all 4 sensors with OEM if needed. Always at least a hose off upon return home...usually through automatic car wash with undercarriage wash though.

Batteries are less than 6-months old. Maybe the CEL has nothing to do with the wheel sensors or CAN bus?

Max Blast

the CEL has nothing g to do with the wheel sensors or CAN bus.

DarthVaderpa

If one or more wheel sensor are bad, it will trigger the ABS and ESP inoperative light as well as the CEL.

Max Blast

ive had sensors fail the ABS and ESP system, but never trigger a CEL. There are other codes in OPs post that in an of themselves will trigger a CEL

- they way to see which codes are causing the CEL in the OBD generic reader, is that they will have a “MIL” ON tag. (Malfunction indication light).

if there’s a manual confirmation of this I’ll yield, but these are separate systems.

BlownV8

I had one fail and my car lit up like a Christmas tree. It was a total failure and had a hard time getting the tranny to cooperate. Replaced the wheel speed sensor, reset the codes, all was well again.

wannawagon

agree with MAX BLAST - had numerous ABS/Traction codes but never had a CEL from them. Are the wheel sensor codes stored and current - or just stored - can't see why no ABS/Traction light/message on dash

Suggest CEL from the ETC - is the cable connection to the transmission sound? water ingress? were you driving in water as well as sand? (connection on front right lower side of transmission )