Yesterday I started my car to warm it up. It ran for about 5 minutes and then when I went to leave there were a number of error messages, SRS malfunction, TCS off, presafe brake inop and some more. I decided to turn the car off and then back on again and when I did it would not turn back on. It doesn't do anything. I can hear the intercooler pump running, the radio is working, the seats are working, the MIL is off.

The battery is less than 2 weeks old and I charged it overnight and today it still won't start with same results. It is cold today (15F/-10C). I hooked up Autoenginuity and there are a large number of communications related codes.

Here is a list, any help diagnosing would be appreciated:

Timestamp: 1/22/2025 05:29:04 Make: Mercedes Benz Model: S Class Year: 2010 VIN: MIL: Off

Diagnostic Trouble Codes

Generic Powertrain U0121 Lost Communication With Anti-Lock Brake System (ABS) Control Module

Freeze Frame for DTC U0121 Calculated Load 32 % Coolant Temperature 28 F Engine RPM 1467 r/min Vehicle Speed 0 MPH

Enhanced Powertrain CAN ME97 P202a (202A) Unknown Trouble Code Description. Please see your factory service guides for more any information. P20a8 (20A8) Unknown Trouble Code Description. Please see your factory service guides for more any information. P209a (209A) Unknown Trouble Code Description. Please see your factory service guides for more any information. P2080 (2080) Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 1)

Fuel Pump Control (FSCU164) U0168:87 (C168) Communication With The Electronic Ignition Lock Has A Malfunction

Transmission (EGS53) U0164 (C164) Communication Disturbance With Control Module N19 (Air Conditioning Control Module).(CAN Timeout Fault) U2318 (E318) Fault In CAN Communication With Component N15/5 (Electronic Selector Lever Module Control Unit) Or A80 (Intelligent Servo Module For DIRECT SELECT). (CAN Timeout Fault) U0121 (C121) CAN Communication With The Traction System Is Faulty.(CAN Timeout Fault) U0141 (C141) Communication Disturbance With Control Module N73 (EIS [EZS] Control Unit).(CAN Timeout Fault) U0155 (C155) Communication Disturbance With Control Module A1 (Instrument Cluster).(CAN Timeout Fault)

Shift Module A80 (DSM) U0121:87 (C121) Lost Communication With Anti-Lock Brake System (ABS) Control Module U0168:87 (C168) Lost Communication With Vehicle Security Control Module U113b:87 (D13B) Unknown Trouble Code Description. Please see your factory service guides for more any information. U0155:87 (C155) Lost Communication With Instrument Panel Cluster (IPC) Control Module U0111:87 (C111) Lost Communication With Battery Energy Control Module A U0128:87 (C128) Lost Communication With Park Brake Control Module U0146:87 (C146) Lost Communication With Gateway 'A'

Electronic Parking Brake (EFB221) C1823 (5823) No CAN Message Was Received From Control Unit N47-5 (ESP Control Unit) C1822 (5822) No CAN Message Was Received From Control Unit N15/3 (ETC [EGS] Control Unit) C1842 (5842) No CAN Message Was Received From Control Unit N80 (Steering Column Module) C1826 (5826) No CAN Message Was Received From Control Unit N47-5 (ESP Control Unit) C1841 (5841) No CAN Message Was Received From Control Unit A80 (Intelligent Servo Module For DIRECT SELECT) C1821 (5821) No CAN Message Was Received From Control Unit Engine Control Module C1825 (5825) No CAN Message Was Received From Control Unit N73 (EIS [EZS] Control Unit)

Airbag (AB221) B1006 (9006) Undervoltage at Tterminal 30 B1007 (9007) Undervoltage at Terminal 15R B119c (919C) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B1181 (9181) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B1182 (9182) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B1187 (9187) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B1188 (9188) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B1189 (9189) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B118a (918A) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B118b (918B) No CAN Message Was Received From Control Unit N73 (EIS Control Module) B11b6 (91B6) CAN Controller: CAN Bus Offin The Case Of The Fault 'Bus OFF' The Control Module Is Isolated From The CAN Bus Because Of A Major Communication Fault

Air Conditioning (KLA221) B100b (900B) Terminal 30 Has Undervoltage Or Overvoltage B120a (920A) A31/1m1 (Circulation Pump): Overload(Overload Is Detected At A Current greater than 2 A.) B1395 (9395) A31/1m1 (Circulation Pump): Short Circuit To Positive Or Open Circuit

Central Controls (CTC) U1000 (D000) Control Unit Central Display is Defective U1909 (D909) Unknown Trouble Code Description. Please see your factory service guides for more any information.

Central Controls Rear (CTCR) U1954 (D954) Fault In CAN Communication With Control Unit N73 (Electronic Ignition Lock Control Unit)

Instrument Cluster (KI221) U001e (C01E) No CAN Message Was Received From Control Unit Adaptive Brake U0026 (C026) Time Out Backbone BSD_LT_STAT U0010 (C010) No CAN Message Was Received From Control Unit Adaptive Brake U0018 (C018) No CAN Message Was Received From Control Unit Adaptive Brake U001d (C01D) No CAN Message Was Received From Control Unit Adaptive Brake U0011 (C011) No CAN Message Was Received From Control Unit Steering Column Module U0012 (C012) No CAN Message Was Received From Control Unit Engine Control Module U0025 (C025) No CAN Message Was Received From Control Unit Engine Control Module U0038 (C038) Vehicle Communication Bus B Performance U0003 (C003) No CAN Message Was Received From Control Unit EZS

ASSYST (WIA) B0704 (8704) Control Unit ASSYST Is Not Receiving Any Messages From The Engine Compartment CAN Bus

ASSYST Plus (WR) B0506 (8506) Communication Error With Instrument Cluster

Overhead Control Panel (OCP221) B1001 (9001) The Voltage Was Less Than 9 V During 5 S

Upper Control Panel (UCP221) B1030 (9030) No CAN Message Was Received From Control Unit N93 (Central Gateway Control Unit).Failure Of CAN Message 'Status 'SRS Indicator Lamp B1043 (9043) Button 'Right Front Reading Lamp' Remains In The Switched State (Contact Sticks)

Signal Acquisition - Driver (SAMF221) B1041 (9041) Component M13 (Heating Water Circulation Pump) Has An Overload Or Short Circuit Or The Line To The Component Has A Short Circuit Or Open Circuit B1090 (9090) Component E6/1 (Left Front Side Marker Lamp USA) Is Faulty Or The Line To The Component Has A Short Circuit Or Open Circuit B10d0 (90D0) Component Switch Illumination Or Line To Component Has Short Circuit Or Open Circuit B1101 (9101) The Coolant Level Is Too Low Or The Line To Component S41 (Coolant Level Indicator Switch) Has An Open Circuit B1102 (9102) The Washer Fluid Level Is Too Low Or The Line To Component S42 (Windshield Washer Fluid Level Indicator Switch) Has An Open Circuit B1121 (9121) Local Undervoltage Of Component M6/6 (Master Wiper Motor) B1200 (9200) Circuit 30 Has An Undervoltage Of less than 10.5 V B1202 (9202) Circuit 30 Has An Undervoltage Of less than 7 V

Steering Column Module (MRM221) U11a3 (D1A3) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1198 (D198) Unknown Trouble Code Description. Please see your factory service guides for more any information. U0146 (C146) Lost Communication With Gateway 'A' U0168 (C168) Lost Communication With Vehicle Security Control Module U1027 (D027) Unknown Trouble Code Description. Please see your factory service guides for more any information. U0142 (C142) Lost Communication With Body Control Module 'B'

Gateway (CGW221) B1010 (9010) Low Supply Voltage, Less Than 9-10 Volts

Audio Command Display ZAN (DISPC211) U1010 (D010) The Supply Voltage of the Control Unit is Too Low

Head Unit (HU204) U1219 (D219) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1155 (D155) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1152 (D152) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1022 (D022) MOST Communication Has A Malfunction (Ring Break At Position 5)

 

It sure looks like a low voltage issue to me. I would charge the battery and check the voltage after charging. If you can get it started, I would check alternator output. Check serpentine belt for slippage or slack. Erase the codes. Let us know what you find.

I can tell you my W221 does not like the cold weather at all.

 

get rid of any puddles under the carpets (normal merc feature as the car age)
fit two new batteries (normal maint - big one at the front, another small one under the dash)
clear the gunk (they collect so much detritus when having a temper tantrum you can't get anywhere for the noise - most of which are lies when the batteries go flat and water gets at canbus junctions under the carpets)
go for a drive come back with latest batch of diagnostic lies

ISMs - die
electroplate speed sensors in the gearbox - die
ABS sensors - die

but nearly all those can be linked to low volt temper tantrums... Never bother with diagnostic checks on these models unless you add a big battery charger in to the mix with known to be perfect fully charged batteries

 

Battery is 11.95 now, after a half hour of the ignition being on while trying to start and pulling the codes. It was 12.7 before I started trying to get it running this morning (after charging overnight). I will erase the codes again tomorrow and see what I get.

 

anything under 12.3V and its game over for accurate diagnostics - you'll just make up more lies

 

Thanks.

The battery in the engine compartment is 2 weeks old.

I did not know there was a battery under the dash, do I need to pull the dashboard to get to it? I will try to replace it, but it will probably have to wait until this weekend because it is outside and too cold to work on right now.

I don't think there is any water in the floorboards ... and it would be ice right now.

 

its near the ignition switch (baby bike battery - helps the gearbox ISM behave when the other one is having a moment) some say they can reach by undoing the fuse box at the end of the dashboard... open the door look at end of dashboard that trim cover unclips easily and you see a fusebox - take note of the layout as many forget how it goes back in - would be best to disconnect the front too one before making any mistakes - local dealer should have them in stock

connect up and charge the car using this connection set up (and leave on when doing diagnostics - not meant to connect anything any other way) if yours looks nothing like this and the battery is only a 35 amp one then its the old set up and there's a huge battery in the boot.... but a 2010 should be the set up in the picture and video....










FYI - the older twin battery cars you ONLY connect like this picture

 

Given the cold temps if the starter battery is new but defective, this is exactly the kind of codes you would get. Don't know how convenient it would be, but I might remove the battery from the car and take it to Batteries Plus or Advance Auto and have them do a load test on that "new" battery. I recently bought a new battery for my son's BMW, and it failed in the first 24 hours. They honored the warranty, but what a hassle!

I don't think you have a trunk battery. I do think you have an under dash small motorcycle sized battery for your transmission shifter. You can access it from the side of the dash with the door open. There are posts to describe the access. Not hard. But a hassle in the cold.

I would recharge it, erase codes, and try to start it. If it starts, I would re-check codes. Keep us posted.

 

I had it on then charger all day while I was at work and the battery is still not showing fully charged. Will try this tomorrow afternoon and then take it to advance if it is not working.

 

Keep us posted. I am betting it was a defective new battery and the cold weather exposed it. Now if your alternator is also bad or the belt is slipping, that would likely kill a new battery whether it was defective or not. And it would take about two weeks to show up even in cold weather. So after you get her started, check the output of the alternator with a simple Voltmeter or use the scanner to show voltage while running.

My W221 hates this cold weather also. I went to cold start it in 15 degree weather, and she complained but started but showed a red trunk light image on the dash. I am guessing a buildup of ice but who knows. The message went away after the car warmed up. As I get older, I don't like cold weather either......

 

if charging in the car (or as battery support with key on) use the correct terminals...as shown in post #7 - that way the car drain is included in what the charger thinks is happening

 

The battery is green on the charger when I got home today, indicated 12.5V on the multimeter and it got a lot warmer (45F/8 C). Still showing warnings on dash. I cleared the codes, they came back immediately. I tried to start and got nothing.

I pulled the battery and I am going to take it into AA to get tested tomorrow.

 

swap the silly little one under the dash...

 

I had the battery checked yesterday it is good

I put the battery back in the car today. The dash warnings went away and the car started, the presafe brake and other related features are online. It idles fine but there is no response to throttle input. The car shifts fine through P-R-N-D. Most of the trouble codes went away.

I am using an autoenginuity scanner with the enhanced Mercedes package. It is not showing anything for the throttle pedal position sensor. A lot of the other powertrain sensors are not showing up on the scanner either. The OBD-II sensors are showing up though. Alternator putting out 14.5 Volts and shown both on the dash and in the OBD-2 scanner readout.

I am going to try to replace the little battery in the instrument panel today. I have not messed with any wiring recently except around the battery and that looks ok. If the new little battery doesn't fix it I think it is probably a problem with the communication system or a module (SAM maybe?)

Most of the codes went away following are the only ones remaining:

Electronic Parking Brake (EFB221) C1821 (5821) No CAN Message Was Received From Control Unit Engine Control Module

Air Conditioning (KLA221) B1395 (9395) A31/1m1 (Circulation Pump): Short Circuit To Positive Or Open Circuit

Signal Acquisition - Driver (SAMF221) B1041 (9041) Component M13 (Heating Water Circulation Pump) Has An Overload Or Short Circuit Or The Line To The Component Has A Short Circuit Or Open Circuit B1090 (9090) Component E6/1 (Left Front Side Marker Lamp USA) Is Faulty Or The Line To The Component Has A Short Circuit Or Open Circuit B10d0 (90D0) Component Switch Illumination Or Line To Component Has Short Circuit Or Open Circuit B1101 (9101) The Coolant Level Is Too Low Or The Line To Component S41 (Coolant Level Indicator Switch) Has An Open Circuit B1102 (9102) The Washer Fluid Level Is Too Low Or The Line To Component S42 (Windshield Washer Fluid Level Indicator Switch) Has An Open Circuit B1121 (9121) Local Undervoltage Of Component M6/6 (Master Wiper Motor) B1200 (9200) Circuit 30 Has An Undervoltage Of less than 10.5 V B1202 (9202) Circuit 30 Has An Undervoltage Of less than 7 V

Steering Column Module (MRM221) U11a3 (D1A3) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1198 (D198) Unknown Trouble Code Description. Please see your factory service guides for more any information. U0146 (C146) Lost Communication With Gateway 'A' U0168 (C168) Lost Communication With Vehicle Security Control Module U1027 (D027) Unknown Trouble Code Description. Please see your factory service guides for more any information. U0142 (C142) Lost Communication With Body Control Module 'B'

Gateway (CGW221) B1010 (9010) Low Supply Voltage, Less Than 9-10 Volts

Audio Command Display ZAN (DISPC211) U1010 (D010) The Supply Voltage of the Control Unit is Too Low

Head Unit (HU204) U1219 (D219) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1155 (D155) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1152 (D152) Unknown Trouble Code Description. Please see your factory service guides for more any information. U1022 (D022) MOST Communication Has A Malfunction (Ring Break At Position 5)

Satellite Digital Audio Radio N87/5 (SDAR221) U1010 (D010) The Power Supply is too low U1250 (D250) This Control Module Does Not Match To The Coded Model Designation

 

Sounds like the car is in limp mode but that would set a CEL and you would see it in a PCM scan. I would have thought your scanner with the Mercedes version would have been enough but if it was me, I'd get a friend with DAS to scan it or sign up with the Benzninja. I wish I could be more help, but I am not sure why it is doing what it is doing.

 

Thanks Vettebk, you've been a lot of help already.

I pulled out the dash battery and put in a replacement from batteries plus. After I put that in it initially started up and drove normally with no problems, after a few minutes of driving I lost pre safe braking, adaptive cruise and had a right SRS malfunction, it still drove fine though, and restarted again after I shut it off (continued to get the SRS and presafe warnings). I have no CEL and have not had one the entire time.

The Presafe braking and cruise has been flaky for years, and turns itself off occasionally (not often, like once a month maybe). It usually comes back on after a few minutes driving or when I turn the car off and turn it back on. The SRS has never had a problem before.

I have not pulled the codes since the last time I drove it. Assuming it keeps driving I am going to drive it this week and see if it clears itself after a few starts. I am also going to look at some of the wiring diagrams in WIS and look at the SRS system and presafe brake and see if there are anything common that could cause a failure in both.

 

Looks like BOTUS was right as is normal here about your Aux little battery in the dash. I am still flummoxed about why the very strange codes but I am super relieved to hear you are running and driving. Please keep us posted if things start to reset.

 

never heard of your diagnostic tool - so can't tell if its giving all the info - all the codes for the front sam are a concern... I'd double check for puddles in the big box near the brake mast cyl - and as so easy to do, look under front passenger floor carpet (just pull it back undo the plastic nuts and look behind the alloy plate (should look like brand new - not a corroded soggy mess)

and the pre-safe issue is also a bit weird.... its part of the radar set up of distronic plus, tries to work out if you're crashing and sets the car up for a more comfy smash - I'm guessing ABS sensor or crash sensor throwing ESP a curve ball - ever had a tiny prang ? its enough to make the chassis leg sensors throw teddies easy and cheap to replace but it will have a code for them

 

Thanks. Will look for water tomorrow and scan again when it is light and warmer. I also have an ICARSOFT with the Mercedes module I can try instead of the Autoenginuity. That one is a pain to plug in and more difficuly to navigate, but it may give a bit more troubleshooting info.

Pre-Safe is what the warning on the dash is saying is inop, but Distronic is also not working and I don't think the blind spot monitors are working either.

According to WIS the DTR (distronic) control unit is powered by fuse F66 in the engine fuse compartment and either relay D or E. These are in the same location as the Front SAM where most of the remaining codes are coming from. Conincedence??

I can't find a relation to the SRS (and now the dash is saying specifically front passenger SRS malfunction).

 

(did you ever check the cluster menus - some bits can be turned off - but I doubt that should show as error in diagnostics).

Pre safe involved in most things - its the beep from the overhead control panel - than can be enabled or not, (with cluster logo to help understand why it beeps incessantly). It watches your driving waiting to see if your driving style or other road users get in your way (within it pre build rules), it either beeps (which changes in number and cadence based on the edition of software in the Rear SAM) or when it really believes you are going to crash AND you then bother to start to brake - it smashes the brake pedal to the floor - moves the seats to a better crash position - pumps up the seat cushion bolsters - snatches the seat belts tight - arms air bags for a big reaction - unlocks the doors - and closes the windows . It certainly makes the passengers get a fright even if you can see you'll stop comfortably.

 

Pre-safe and distronic cruise use the same radar thing to decide if you are going to cruise in traffic or to keep a driver who is not paying attention from having as big a crash. Time to plug it in to XENTRY. Peter can sniff out issues and point you in the right direction. He is excellent.

Botus... My 221 S-65 was very good at letting me know when I was being a savage as ‘Pre-Safe’ with all the noise, seats moving ect would do it’s thing with many turns. Until I turned it off.

 

@auburn2 replace the main battery. It’s no good.

 

The problems are all gone. When I got up this morning I checked the area around the master cylinder and the driver floor for water, both bone dry. I opened the front engine fuse panel and swapped relays D & E. I also pulled the distronic fuse and tested it, it was good and I visually inspected all the other fuses without pulling them. After all this it started it up and it ran fine with no problems. It still has some historical event data stored on both the SRS and the SAMF, but everything is working now. Not great in terms of piece of mind, but not anything left to troubleshoot either.

After being charged the main battery tested good. 1100CCAs (rated for 900), 12.8V, reserve capacity good.

It is a lot warmer today (50F/10C). This might be my car's way of telling me Alabama is too far north and I need to move to Miami .... something my bones and the rest of my body are telling me too.

I am going to cross my fingers and hope for the best. Thanks for the help everyone.

P.S. When I got rearended by a Tahoe on the highway and totaled my 2007 S65 all that stuff you talked about Botus happened even though I was hit from behind. The worst was after it ran my seat back I could not reach the pedals well to brake. It also called the mercedes roadside assistance automatically and before I am even stopped I have someone talking to me. It was thoroughly confusing and frightening: No one was hurt, but I am trying to keep from hitting other cars, get it to the side of the road without being able to reach the brakes and I have some unknown person (maybe God ??) talking and asking me if I am ok.

 

I depart for Cape Coral, FL this week. It is simply too cold here in Washington, DC. I am taking the S600. Really looking forward to getting her on the highway for an extended run. I will report back on MPG.

I think your W221 is telling you it is time to go South.