Help!

I have a 2010 ML350 BlueTec diesel auto. Had an ABS fault light and warning message the other week, and when I tried to pull away, the brakes applied themselves.

I tried again, same thing. I did what most would do, check everything, make sure it wasn't me being stupid, but it continued to happen.

I had only bought it 24 hours prior, so it went back. They have replaced 3 out of the 4 speed sensors, and the yaw sensor.

Guess what, it happened again, albeit not as violently.

I have noticed it happens when pulling away from a stand still, and on an incline. That may be coincidence, but I'm inclined (no pun intended) to think the gradient has something to do with it.

Has anyone experienced similar? Is it an ABS module fault? Hill start fault? Something else?

Also, it has now developed a fault selecting D and R from the column mounted gear selector. Research tells me it's either the auxiliary battery, or gear selector module on the side of the gearbox. The mechanic seems to think it's connected to the speed sensor issue.

Any help or advice would be appreciated

 

Advice? Return the lemon and walk away. Now.

 

Sounds like the Hill hold feature not releasing correctly.

The car knows you're taking off when the brake pedal is released and the accelerator is subsequently pressed.

1. Ensure your brakes lights actually switch off when the pedal is released.
2. Replace brake pedal switch?
3. Faulty stop-light wiring (water damage?)

 

Did the mech. supply you with the various code numbers?

 

It's a serious option :-(

 

Yes, I've got a diagnostic report. Many faults, although some are probably historic and haven't been cleared, some are current

 

Are the current ones a secret??

 

LOL not at all, didn't know whether to post here or not, it's quite large and may not interest many people, but here it is....

Diagnostic Codes
RAC DIAGNOSTIC SYSTEM
System Type: GEARBOX
Name: GEAR SELECTOR - DIRECT SELECT CONTROL UNIT
DTC: U0100,Engine control unit; communication faulty
DTC: U140B,Rear left wheel speed sensor; implausible
DTC: U1409,Front left wheel speed sensor; implausible

System Type: ENGINE SYSTEM TEST/VALUES
Name: 642.940 - CR4 - 3.0L - 165 (224)
DTC: 2095,Intake air temperature sensor, value is below limit
DTC: 2094,Intake air temperature sensor, value is below limit
DTC: 2051,Rail pressure monitoring; rail pressure too low
DTC: 2021,Rail pressure monitoring; rail pressure too low
DTC: 2043,Camshaft sensor; no signal
DTC: 2644,Left mass air flow sensor, value is above limit

System Type: GEARBOX
Name: GEARBOX - GEARBOX
DTC: D409,No or incorrect CAN message from control unit ESP
DTC: D40A,No or incorrect CAN message from control unit ESP
DTC: D40B,No or incorrect CAN message from control unit ESP

System Type: BRAKES
Name: ELECTRONIC STABILITY PROGRAM - ELECTRONIC STABILITY PROGRAM
DTC: 5121,Rear left speed sensor
DTC: 6001,The supply voltage of the control unit is too low (undervoltage).
DTC: 7268,One ore more speed sensors have implausible values
DTC: 7266,ESP disturbance
DTC: 5105,Front left speed sensor
DTC: 5106,Front left speed sensor
DTC: 5125,Rear left speed sensor
DTC: 5116,Front right speed sensor
DTC: 5126,Rear left speed sensor
DTC: 5120,Rear left speed sensor
DTC: 5122,Rear left speed sensor
DTC: 5102,Front left speed sensor

System Type: CENTRAL ELECTRONIC UNIT
Name: SIGNAL ACQUISITION AND CONTROL MODULE - FRONT - SIGNAL ACQUISITION AND CONTROL MODULE - FRONT
DTC: 9006,Left side low beam, defective
DTC: 900E,Right front side lamp and parking lamp
DTC: 902A,Wiper relay on/off
DTC: 9043,Terminal 30: undervoltage< 7 V
DTC: 9045,Terminal 30: undervoltage< 7 V
DTC: 904A,Engine Coolant Level Low

System Type: CENTRAL ELECTRONIC UNIT
Name: SIGNAL ACQUISITION AND CONTROL MODULE - REAR - SIGNAL ACQUISITION AND CONTROL MODULE - REAR
DTC: C361,Terminal 30: undervoltage< 8 V
DT

 

Mark, there are too many codes. Clear them all, take it for a short ride and as soon as the problem occurs, read the codes.

I believe that the mech. never changed the Yaw sensor as the price is approx. $350.

 

Oh no. The dreaded Obi-Wan Bratwurst-and-Sauerkraut Fault. The computer has sensed a disturbance in the Grille. You'll never make light speed again on *that* ride, young padwan...

 

Yes, good plan. Far too many faults

 

I would suspect the dealer cleared a lot of codes, then sold you the truck.

If you have only owned this for 24h, you probably haven't put much mileage on it...

My next step would be to park the truck where you bought it, walk inside and show the dealer all of your diagnostic printouts, then tell them you want a FULL refund or you will leave and have a lawyer contact them.

Don't let them do a temporary fix, send it to 'their guy' to look at, etc. They'll just clear codes and make it go away until you go away