ABS/ESP/Run Flat Indicator inoperative

[Megz92]

Hoping someone can help me please!

I have a 2006 S-Class S320 CDI (W221).
Bought it a few weeks ago and up until now the car has been sitting since its last MOT in July.

When we got the car there is a message on the dash saying ABS/ESP inoperative. Run Flat Indicator inoperative. We don't have the owners manual for the car so can't consult it as it says.

Partner plugged his diagnostic into the car and it came up with a faulty wheel speed sensor passenger rear. We bought a new sensor and fitted it, reset the fault but fault still on the dash. It'll turn off until the car moves a few feet and it'll come on again.

The car went into limp mode one day coming out of the fuel station. Managed to get off the road and phone partner but of course by the time he arrived to save the day it was fine again and no faults found on the car. Not had it do this again for a couple of weeks until today again.

While driving the dash came up with the manual/electronic handbrake and the car wouldn't change gear. Restarted the car mid driving as I was in peak traffic and it went away but then went into limlp mode. Again, checked diagnostic, no faults other than the esp/abs/electronic break system. When I started the car again the steering went heavy and went back into limp mode. Stopped the car again and turned it off and it sounded like it was overheating but temperature was sitting just over 80degrees. At one point while driving on the dual carriageway the glow plug light came on but soon went off again.

Anyone have any ideas as to what's going on?

 

[SpikyMikey]

Pretty sure you're going to find it's a battery issue, given the amount of time the car has been sitting. Try to get the battery on charge for a decent amount of time and try again. Hopefully your electrical gremlins will disappear- modern cars with all their electrical systems hate battery undervolts. If you have a trawl though some of the threads here, you'll see it's a common problem currently. Good luck

 

[Megz92]

Pretty sure you're going to find it's a battery issue, given the amount of time the car has been sitting. Try to get the battery on charge for a decent amount of time and try again. Hopefully your electrical gremlins will disappear- modern cars with all their electrical systems hate battery undervolts. If you have a trawl though some of the threads here, you'll see it's a common problem currently. Good luck

We actually had to do this already as the central locking wouldn't work. Changed the battery behind the back seats when we tested it it was only reading 3 volts was the original MB battery. Took the battery out my partners MB as its SORN and that battery is brand new so we know its not the battery. The other battery is relatively new too so don't think it'll be that. We'll be testing that one to be sure but we're confident it's not the battery.

We don't want to mess about with the battery too much as we don't have the codes for the radio/Comand Centre so if it's disconnected too long we're worried we're left without sound in the car.

 

[Gbrowncls55]

This seems a bit simple as a suggestion particularly as you seem well versed in the way of the Benz! but the fact that the steering went heavy and the car went iinto limp home with overheating would indicate a possible pulley or belt problem. Same symptoms as I had when my crankshaft pulley came loose....just before it sheared. that was also a 320 but a R129 SL

 

[mbmbc123]

When one of my wheel speed sensors went, one of the symptons was lack of power steering. Not always, sometimes. Who kniws what the ECU is thinking :-(

 

[MilesWFB]

I had similar problems and the cause was that the alignment was off. only an idea

 

[Megz92]

So we're literally just back from looking at the sensors, batteries (both over 12v, back showing over 13v and front over 14v) , doing more diagnostics. Figured out that the abs ring is knackered. It's separated and spinning in the shaft so have ordered new rings for both sides and new fault (abs/esp etc) came up for the other side too. So will be replacing the rings and bearings too as they'll need done for next mot anyway so really hoping that sorts the issues!

 

[markjay]

....batteries (both over 12v, back showing over 13v and front over 14v)...

The battery voltage should be checked with the engine switched-off. The voltage you listed above is what the alternator is producing while the engine is running, and it tells you nothing about the condition of the battery. A fully charged battery (with the engine switched-off) should show 12.7v. Anything less than that means that the battery isn't fully charged. And, as said, 13v and 14v isn't the battery's voltage, instead it's what the voltage regulator in the alternator is producing.

 

[Megz92]

The battery voltage should be checked with the engine switched-off. The voltage you listed above is what the alternator is producing while the engine is running, and it tells you nothing about the condition of the battery. A fully charged battery (with the engine switched-off) should show 12.7v. Anything less than that means that the battery isn't fully charged. And, as said, 13v and 14v isn't the battery's voltage, instead it's what the voltage regulator in the alternator is producing.

The car was off at the time as it was up on ramps

 

[markjay]

From here:

Easy Ways to Test Your Battery Voltage (Step-by-Step Instructions) | Go Auto

Checking your battery’s voltage is a relatively simple task. If you have the right tools for the job, there’s no reason you can’t do it all by yourself. Today, we’re going to show you a few easy ways to test your battery voltage.

www.goauto.ca

 

[OneForTheRoad]

The car was off at the time as it was up on ramps

thats brill . a 12v battery that holds 13 and 14 volts . canny that . the acid maybe ran to the back of each battery , with the car being tilted on ramps ?

 

[Mitko785]

Hi Guys
I have SRS ON on my car is c class 2014 model .i have tried to reset but its not working. I have fault B1 BC749 does anyone know what kind of fault is that
KIND REGARDS

 

[markjay]

thats brill . a 12v battery that holds 13 and 14 volts . canny that . the acid maybe ran to the back of each battery , with the car being tilted on ramps ?

This can happen if an AGM battery is swapped without following the correct reset procedure using STAR.

The Battery Management Module will keep on memory the old battery's parameters in memory and will manage the charging incorrectly. It should sort itself out over time but in the meantime it's overcharging and damaging the new battery.

 

[Numair Aidroos]

The car was off at the time as it was up on ramps

W221 speed sensors are very tricky. Just reset the tire pressure from the command it should go back to normal.