Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Hi we have a 2007 Mercedes C280 it's has a intermittent problem with stalling so far only at stop lights. There's no codes set in the PCM and the MIL light has never come on. In fact the Mercedes dealers factory trained service technicians could not find any source of the problem with all of their high end factory scan tools and documentation.
I'm trying to figure out how to diagnose this problem. It has a key fob which has an infrared transmitter for security. The battery in the key fob was recently replaced but for some reason the unlock button has not been working properly. Could the key fob be the cause?
The fuel pump recently failed and was replaced by the dealer. Perhaps they miss something in the fuel pump replacement. It was $700 parts and labor for the new Mercedes Factory fuel pump. It did not solve the stalling issue. Previously it would stumble while in a turn. The car is never run to empty. The fuel tank is always kept topped off regularly.
I love the scanner danner videos and I am a subscriber to your Channel great videos I consider you one of the best experts in diagnosing these types of issues. I hope that you may have worked on similar issues and have some pointers to get us going in the right direction. Looking forward to hearing from you.
Thank you
Last edit: 5 years 4 months ago by darnold. Reason: Add Icon
It sounds to me like it would be worth checking fuel pressure when it happens. Going around corners and stopping at lights bring to mind movement of the fuel in the tank. Otherwise possibly related to lifting your foot off the accelerator pedal - maybe it's not seeing idle position?
Getting involved in discussions because I have a lot to learn still.
I would be first investigate if this is an idle speed control issue or just dirty throttle body . At idle speed the engine computer has to compensate for added loads on the engine from ancillaries such as electrical loads on the alternator, air conditioning and power steering. Stalling when turning street corners at close to idle rpm can often be due to the increased loads from the power steering.
So a good plan of attack without a bi-directional scan tool would be first to check the connectors for the power steering pressure sensor and ac pressure sensor are fully plugged in and making a good connection and then clean the throttle body.
" We're trying to plug a hole in the universe, what are you doing ?. "
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