Code 150200 Upper limits value components HFM SFi has been exceeded
 

I have ML 320 Blutec with OM 642 diesel engine.

I have this code per my code reader. I can't even clear this code, it goes away and come back right the way on code reader even if I will not turn a car on. If restarted a car Check Engine will be illuminate again. I have normal driving, no loss power and all work as is. I replaced about month ago EGR valve (what is pain.)
Used start system to adopt a new EGR. Everything was fine until few days back.
its hard fault and no solution.I tried disconnected plugs from MAF and boost sensor and nothing help - Upper limits value components HFM SFi has been exceeded is still there .


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HFM_SFI is a term generally used to describe the 1992 - 96 ish gas engine injection system in it's entirety. I think there is a problem with the scan tools description and it should state MAF / air flow meter.

Look at the live data and see if the MAF produces believable voltages. Generally, a MAF will output 0.5 V with no air flow and 4.5 V at max but your car might be different. If the computer sees < 0.5 or > 4.5, it triggers a voltage too low / lower limit or voltage too high / upper limit code.

It would be a good idea to measure actual voltage output of the MAF as on other cars, I've had a component failure and the ECU generate a substitute value that the scan tool picks up.

I replaced my MAF's with older ones, as I replaced Y pipe. So it's not MAf's. It might need it reprogram all system ? Any MB mechanics here? Need a help. I'm in Sterling area VA. I'm thinking to take it to dealership but i'm afraid they will start swapping part around and no fix near future.

Did you read my post 2 at all?

yes I need to get Star diagnostic to check.

Air mass faults indicate EGR flow problems on this platform.

I'd
#1 remove and clean the EGR elbow on the front of the engine.
#2 reset air filter and air mass adaptations (SDS required)
#3 flash update CDI with the latest software (SDS and Xentry access required)

i got this fix. My tech resent all adoption control for engine, and be able to clear a code. So I drove around 1,000 miles over weekend and so far no code.
it might be need a new software from MB.

well it came back after 300-400 miles. It's definitely a swirls flaps on intake or engine ECU per dealer. They told me they can do swirl motor and clean intake for couple thousand dollars and than try re program ECU but no guarantee.
So I was sad and mad, than stop by Jeep dealer as same motor was used on some Jeep. But instead fixing I got trade deal and traded for Jeep GC diesel with warranty.