Greetings
I have been doing a ton of research online but i have not been able to find anything with my issues.
For the past lets say 3 months ive been having issues with my 1998 320i that were getting progressively worse. At first it was just a bouncing and sometimes stalling idle when cold then at some point the car started doing this:
-no problems occur on completely cold first start of the day except the idle bounce(no stalling now that its summer), problems occur only when the engine is warm but might also not occur when it is warm
-the asc and ONLY THE ASC LIGHT comes on and stays on, this is usually accompanied by a sudden jerk as if u were to let out the clutch too quickly
-after this above the car(from my reasearch this is not limp mode or anything like that)exhibits an extreme loss of power and climbs the revs as if it were climbing stairs, during all of this the asc system seems to be working normally still preventing skids but the light is constantly on
-in total this specific problem happened 4 times with no apparent cause both at highway speed and city speed->(before this the car works perfectly fine)WITHOUT THE ASC LIGHT ON the car would just start losing revs with the gas pedal to the floor and would continue doing this(in the mean time the rev meter shows constant 4000rpm) untill the engine is shut off and turned on again after which the car acted normally
-at first the problem would go away if i went out of the car locked it unlocked it and started driving again and if the problem reoccured id just repeat the process
-i took the car to a reputable independent mechanic he replaced the dme and the throttle body, but the issue did not go away, he said the MAF is also shot so he disconnected it(if this was the main problem the car should exhibit no problems except low low end torque and bad mileage?)
-when this ASC light occurs it will start badly like an old airplane engine usually untill its completely cooled down but not always
-i tried disconnecting the lambda sensors, no change
-i tried pulling out the ABS/ASC fuses, no change
-i took it to a different mechanic just to scan for codes before the problem was this serious and it gave out this:
-ASC-94 ASC: Error of CAN data from DME/DDE CAN DME/DDE CONNECTION B3450_00146
-i do not know atm what codes the mechanic that replaced the dme and throttle body got
Does anyone have any ideas on what my problem might be? Everything that exhibits similair symptoms to what i have always has a CEL which i did not get to this day. The mechanic says it could be faulty crankshaft position sensor, but from my research if its this the car does not even start?
Any help would be greatly appreciated thanks in advance
Last edited by dmav; 07-30-2018 at 01:52 PM.
anyone? anything?
Check harness/connector on ASC control unit for clean, snug connection.
Make sure of no corrosion or bent-broken pins.
No,
the code is indicating an error with communication/data connection,
how would pulling the fuse solve that error?
The error occurs because the DME is initiating the communication and receives no response, therefore a CAN ERROR!
disabling things doesn't end anything.
Since i did not attract much attention i decided to post a video of the issue when its allready present. I dont think you can hear it but when revving it from idle up to like 1200rpm theres a slight stutter, also im flooring it the revs dont go up as fast as normal. Any help would be appreciated thanks in advance.
I don't really see a problem,
I would clear codes, reset adaptations, perform a short drive cycle,
next day-engine cold, perform another short drive cycle, scan for new codes.
What do you mean you dont see a problem? The car doesnt start properly and doesnt run properly if it helps i can try and take a video of the car in motion as the main problem would be far more evident. Btw today i noticed that before the problem begins, and on the sudden jerk, the ASC light comes on(i did nothing that would require the ASC to intervene)then off and then stays on and the symptoms i described above start.
P.S. i cant do any of that
Update: it seems that the problem is not related to the engine being warm but rather going over a certain rpm(around 3500) if i stay under 3500 the car works fine...any ideas?
Symptom of obstructed exhaust, possibly cats.
Perform an exhaust backpressure test.
Also check abs/wheel speed sensors - wires,connections, for clean + snug fit.
Update: i took the car to a mechanic and it gave out codes for:
-intake camshaft sensor
-exhaust camshaft sensor
-crankshaft position sensor
-airflow sensor(its brand new)
-can data connection error between asc and dme
Thats it for now
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