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I'm beginning to suspect and issue w/ my throttle body actuator/motor. I've had inconsistent power delivery problems, the worst being after a shift under light/mid throttle where the call falls on its face for a second and then recovers.
I replaced the accelerator pedal about a year ago, and voltage sweep seems normal on that. After datalogging today I noticed a TPS spike from 20 to 50% but I could have sworn my foot was steady on the pedal when the power loss occurred.
Question - with key on (pos 2, engine not running), is it safe to assume I will get accurate OBD readings of the TPS? Or does the motor need to be running? I ask because the numbers I'm seeing are concerning, mainly I apply the pedal slowly and will see 2, 5, 10, 12% but then it spikes to 96.7% and stays there for the entire 'back' half of the range of the pedal. So what feels like 40% throttle is showing on my scanner as full throttle... Voltage PIDs show a normal sweep for the accelerator signal, but the M16/6 throttle valve actuator voltages show the same dead spot.
Do stock throttle bodies go bad on these motors often?
Actually, I think the log I just got on my drive home is my smoking gun, it's brief enough my datalogging hasn't always captured it. Green line is Throttle Position, and this log is a smooth start from a stop, in comfort mode, with me keeping the gas pedal steady...
1) Any chance this is wiring related, or should I just start with a new throttle body?
2) Anyone wanting to get rid of/sell their stock TB after upgrading??
Actually, I think the log I just got on my drive home is my smoking gun, it's brief enough my datalogging hasn't always captured it. Green line is Throttle Position, and this log is a smooth start from a stop, in comfort mode, with me keeping the gas pedal steady...
1) Any chance this is wiring related, or should I just start with a new throttle body?
2) Anyone wanting to get rid of/sell their stock TB after upgrading??
Can maybe try a throttle body reset, calibration and see if that has any effect.
I've done the sneaky ECU thing, and followed a write up on motor calibration as well (it had something to do with unplugging the TB, key on, back off, plug in etc and you had to wait for things to click and move).
I'll poke around in STAR though and see if there is anything else, I'm still getting used to using it.
Issue seems to have been resolved (assuming no weird re-learning happens).
FYI our W211s don't have a 'throttle body reset' in STAR by themselves like some other models, there are a few tests available w/ actuations and values, which I did first but both passed. They only test the top and bottom ends of the range. You have to navigate into the learning section of adaptations and do an entire load range learning reset which includes the TPS and a few other things.
Car drives and even shifts way better than it has, no more hiccup or loss of power thus far. Fingers crossed!
Issue seems to have been resolved (assuming no weird re-learning happens).
FYI our W211s don't have a 'throttle body reset' in STAR by themselves like some other models, there are a few tests available w/ actuations and values, which I did first but both passed. They only test the top and bottom ends of the range. You have to navigate into the learning section of adaptations and do an entire load range learning reset which includes the TPS and a few other things.
Car drives and even shifts way better than it has, no more hiccup or loss of power thus far. Fingers crossed!
03-03-2020, 04:30 PM
