E220 (W124 AT) Stalls while in motion

[aquavelva]

My E220 (W124 AT) Stalls while in motion. I have observed this twice in the last one month. This seems to be really an alarming/hazardous situation specially as this occurs while the car is in motion. The car starts normally once i have it in "P" position and restart the ignition.

I have observed that the speed at which i was driving was around 30 kmph.

Another problem that i face is that the during idle the engine starts running at high rpm of 20 x 100 (1/min) this happens occasionaly and disappears once i rev the engione to a higher rpm. I had got my throttle body and injection system cleaned recently.

Any suggestions on the probable causes of the problems.

 

[steve333]

Hi,sounds like a faulty crank position sensor(had a simular problem on my old w208 clk320 cab),to be sure get the car put on star diagnostics to find out the exact cause,any good independant garage should have one

 

[grober]

Crank position sensor is a possibility but less likely on these older cars. The "instant restart" isn't typical faulty CPS either. My money would be on a dodgy OVP relay.

 

[aquavelva]

Hi Grober

Could you please elaborate why you bet on the OVP relay. What about the unusual rpms

 

[grober]

A faulty OVP might explain the engine cut outs but not the varying RPMs However the fuel tank evaporative control system= a charcoal filter under the nearside wing + a solenoid valve controlled by the engine ECU on the inner wing sometime goes faulty/leaks causing erratic idling problems. you might want to take a look at that. You could try temporarily blocking off the evacuation pipe which runs from underneath the inlet manifold to the solenoid valve to see if that cures the idle problem. I will see if I can locate a picture/thread on the subject ---- there have been numerous threads on this- found this one http://www.mbclub.co.uk/forums/engine/53623-w124-e220-surging-idle.html

 

[Vlad]

The solenoid valve on the inner wing has MOT stamped on the top if it helps to identify it...as Grober states they can play up. Very easy to replace as they are just a push fit onto the holder on which they sit.

 

[aquavelva]

The sudden cutoff and stalling ->

Grober - I am a newbie and would like to know where the OVP relay is located. Could it also be due to wiring harness ?

Fuel tank evaporative control system= a charcoal filter under the nearside wing + a solenoid valve controlled

I need to locate it. please specify with a pic if possible. There is a smell of petrol fumes in the boot. Could that be the reason ?

 

[BillyW124]

OVP is located behind battery under a plastic cover, it will lokk like a cubic plug or similar.

guys here would be able to confirm.

 

[grober]

Some background on the OVP

OVP relay whys and wherefores - PeachParts Mercedes ShopForum

How to repair a relay including the OVP.

N10 Relay, Soldering Repair, Wiper - Indicators & Hazards - Rear Window Demister. - Mercedes-Benz Owners' Forums


The OVP relay is located behind the flexible plastic shield behind the battery. It can be identified by the presence of 1 or 2 fuses on the top of it. Sometimes it just needs reseating in its socket but usually faults are due to the development of dry joints on the small circuit board inside. A cure is often effected by removing the cover and resoldering the component joints on the board. If this doesn't work then replacement is the only cure. As there are several versions of this relay so make sure you get the correct replacement based on the part no on the existing unit or your chassis number.

here's a picture


for fumes in the boot check all the flexiblepiping ducts associated with the petrol filler cap and neck are in good condition.

 

[aquavelva]

Thank you Grober ! Will do the needful and give my feedback.

 

[aquavelva]

I got the OVP relay cover removed and resoldering of the component joints done on it. Also got the Solenoid valve cleaned. The vehicle still stalled. The surging on idle has not subsided. The car starts immediately after stalling after putting it in P position.

As per the vehicle history, the OVP relay was replaced in mid 2009. Should i look at anything else ? Is a Diagnostic scan necessary ? Does the Charcoal Filter Canister need to be replaced ?

Your specialist adivce is required.

 

[kth286]

smell of petrol in boot is a definite clue.

the tank venting system is quite complex and has valves in-line.

this needs investigating.

how many miles the car done ? as the charcoal canister may never have been changed and now blocked.

and /or pipe come off or split due to pressure etc etc

 

[grober]

Other possibility is some sort of contamination of the MAFF unit. This is the round black plastic cylindrical object with an electrical connection that forms part of the air inlet duct just after the air filter box. This fine tunes the fuel mixture and if its contaminated can lead to erratic running. LOTS AND LOTS of postings about this on the forum if you do a search. Different in detail from model to model they all function in the same way, so don't be put off if any posts refer tomodels other than yours. Check out that fuel tank evaporation filter first tho. Here's a picture towards the rear of the car with the nearside front wing arch liner partially removed [ held on with nylon nuts-easy to remove]

 

[312 Sprinter]

Is the hose to the throttle body on properly? People get them squashed, any air leaks between the a mass meter and the manifold will screw up the idle speed. It will also tend to cause it to stall at idle, but shouldn't when it is under way.

I'd be inclined to have a look at the soldering on the fuel pump relay too. In order for the car to stall when running either the fuel or spark must be getting cut. The question is what is causing that?

 

[aquavelva]

kth286: The charcoal canister was changed in 2008 as per the vehicle history. the car has done 77000 kms

Grober: I will check the MAFF unit and also the Fuel Tank Evaporation Filter (Charcoal Filter)

312 sprinter: The hose to the throttle body is good. The throttle body and injection system was cleaned a month back.The car stalls, While in motion; if the fuel was not being pumped or the spark was improper the car should not have started immediatley after stalling.

 

[aquavelva]

Grober could the stalling be due to MAF or the Fuel Tank Evaporation system

 

[grober]

If the smell of petrol occurred at the same time as you began to experience problems then it might point to a problem with the fuel system. What many people don't realise is that estate versions of the w124 have 2 FUEL pumps. The main one [ along with the fuel filter canister] is in the conventional place in front of the offside[rhd car ] rear axle under the black plastic shield but the other is hidden up beside the fuel tank. It acts to prime the main pump. If either pump wasn't working properly or the fuel filter was choked [ when was it changed last?] that might give rise to intermittent fuel starvation.

If there is a problem with fuel tank venting/evaporation control then sometimes running temporarily with the fuel cap on "loose" =not sealed is a good test- if the problem disappears then that can help pinpoint the problem.

 

[aquavelva]

I got the Diagnostic Scan done and received a big bunch of Error codes mentioned below. Please decipher !!

MB Code 012
Engine Idle Speed contact air mass too large
113
Controller HFM N3/4 not coding
014 IP
Potentiometer implausible high
015 IP
Potentiometer implausible low
017 IP Driver
Potentiometer implausible high
018 IP Driver
Potentiometer implausible low
020 Idling regulation at the lower
024 O2 sensor before CAT G3/2 Probe cold, discontinuity
025 O2 sensor before CAT G3/2 Signal implausible
22 MB Code 027
O2 Sensor (After downstream Cat. Conv.) open circuit
30 MB Code 034
O2 Sensor (After downstream Cat. Conv.) heating current short circuit
035 O2 Sensor regulation mixture too lean
038 Injector Cyl. 1 Y62y1
Discontinuity short circuit to ground
039 Injector Cyl. 2 Y62y2
Discontinuity short circuit to positive

58 MB Code 059
Ignition System output stage 2, Cylinder 4 misfires
59 MB Code 008
Ignition System output stage 2, Current value not reached
070 RPM Signal IN
Output short circuit to ground
071 RPM Signal IN
Output short circuit to positive
147 A/C pressure implausible
71 No description
076
Fuel Pump Relay K27 discontinuity short circuit
74 MB Code 077
CO Potentiometer input short to positive
079
Knock Sensor 1 Signal Discontinuity
082
Spark adv. Deviation too large
79 MB Code 083
Knock control analysis, HFM control unit defective
084 Idle/partial Self Adaptation of short term out of range
086 EGR solenoid Y58/1 discontinuity short circuit
087 EGR solenoid Y58/1 short circuit to positive
86 MB Code 088
Transmission shifting delay smooth switch value , open circuit or short circuit
090 Camshaft timing control solenoid Y49 discontinuity short circuit to ground
91 MB Code 091
EGR switch- valve short to positive
92 MB Code 092
EGR switch- valve open circuit or short to ground
148 Starter output Short circuit to positive
149 Starter output Short circuit to ground
95 MB Code 095
Transmission overload protection switch: Circuit short or open
150 CAN: No receive from EGS
151 CAN: No receive from IAU, KIA
117 Starting attempt with locked 117 accomplished.

 

[grober]

Its possible that the fault codes stored in the ECU have never been cleared and represent the cars entire fault code life history. You need to clear them all and start again. The only one my eye is drawn to is Fuel Pump Relay K27 discontinuity short circuit which is one possible problem discussed before. If my theory of non cleared codes is not correct the only thing to generate such an array of codes would some major car electrical system instability or noise. This could be due to wild voltage fluctuations or arching somewhere which usually points to wiring loom problems. Try clearing all the codes and start afresh. Any real existing fault will soon pop up a code

 

[Tonison]

Interesting, looking out for updates.