Hello everyone,
So I'm continuing my battle with my beloved Volvo C30.
This engine has a fully electronic throttle pedal - the values are correctly registered in the ECU, and engine responds well.
BUT, The values that are registered at the ECU - are not registered at the TCM.
BUT, The readings from the BCM shown correctly in TCM (and match, speed from BCM matches TCM internal)
Any clue how that’s possible?
I suspect that maybe there’s an analog signal from the pedal to the TCM, but I can’t find any information on the pin-out of this TCM (the same one as Mitsubishi SST)
TCM LIVE-DATA (ECU not shown but it responds correctly), WHILE REVVING ENGINE:
SPECS: 2011 MY Volvo C30 - DuraTec HE 4 cylinder 2.0L engine, Ford Getrag 6DCT450 DCT transmission, Ford C1 platform (Volvo "P1" platform with a CEM)
Some cars have multiple pedal position sensors (for redundancy I guess). An OBD scanner will display them as APP-A, APP-B, etc. Sometimes these values are filtered too. So you might see a raw pedal position value, and a calibrated one. So it's possible the TCM isn't using the value you show in the video, and it's using a different one instead. So try to look for different data, or maybe you have to use a different tool. That's just my guess.
To specify, the APP-A is the main one that ranges from 1V-5V (lower value = pedal released, highest value = wide open). The APP-B usually ranges with half the voltage, from 0.5V-2.5V and is used as a safety. This may slightly vary from manufacturers but is the same principle.
What I’m getting on the ECU is the MHz “analog value”, regular value and calibrated - no other pedal position sensor data.
I mean if there’d be multiple sensors connected to the ECU that’d contradict each other, it’d probably set a code.
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The TCM is reading pedal as not pressed and engine torque (calculated value) as 1-10NM instead of the 50-150 that you’d expect during driving…
So I don’t think that there’s two connected to the ECU/CEM.
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This would totally explain harsh shifting, if the transmission with a clutch doesn’t know how much torque the engine is making it won’t be able to connect the clutch in the appropriate manner.
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Maybe there’s a second sensor connected to the TCM, (unlikely) but I don’t have alldata on the Mitsubishi Lancer EvoX to know what’s the pin out of the TCM and what signals it does receive (expect the two CAN buses the TCM reads)
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I really am not sure what diagnosis to give it, expect it being an electronics nightmare.
So, where is the question???
Yep, I edited it to include the question - and it’s basically, “how does something like this happen? And how can I fix it?”