Is there an adaption for MAP/barometric sensor?
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w203 220 CDI
Is there an adaption for MAP/barometric sensor?
w203 2005 220CDI auto.
Having a real nightmare with this one. MAP sensor, IAT, barometric sensor and MAF ALL check out. Have live swapped them with same parts from a running vehicle in every possible combination, not a sensor fault.
Engine off or at idle the MAP should be same as barometric, its not, ecu is reading 138, so '38' over atomsphere.
Have hooked up a fresh ground to each sensor to eliminate that, aswell as a clean +5v source from a power supply, makes zero difference.
ONLY thing that can be causing it is maybe the ECU has changed it learned value of the MAP (the car came in with its original MAP sensor with an actual hole in it), or the sensor wire from MAP to ecu has a short circuit (into something else on the +5v reference), or long shot, the ECU is an EDC16 bosch (very common) and some versions have an internal 'pATM' sensor which measures barometric, maybe this is faulty and causing the ECU to push all the numbers to strange amounts?
Main question, in STAR is there a way of 'adjusting' the default barometric pressure value?
Having a real nightmare with this one. MAP sensor, IAT, barometric sensor and MAF ALL check out. Have live swapped them with same parts from a running vehicle in every possible combination, not a sensor fault.
Engine off or at idle the MAP should be same as barometric, its not, ecu is reading 138, so '38' over atomsphere.
Have hooked up a fresh ground to each sensor to eliminate that, aswell as a clean +5v source from a power supply, makes zero difference.
ONLY thing that can be causing it is maybe the ECU has changed it learned value of the MAP (the car came in with its original MAP sensor with an actual hole in it), or the sensor wire from MAP to ecu has a short circuit (into something else on the +5v reference), or long shot, the ECU is an EDC16 bosch (very common) and some versions have an internal 'pATM' sensor which measures barometric, maybe this is faulty and causing the ECU to push all the numbers to strange amounts?
Main question, in STAR is there a way of 'adjusting' the default barometric pressure value?
Thread Starter
Newbie
Joined: Sep 2020
Posts: 5
Likes: 0
w203 220 CDI
Thanks! Know a guy locally who has a STAR machine, but not sure if he has Vediamo, we're both mostly VAG guys here.
When the MAP sensor is unplugged it drops from 138mbar, to 049mbar which is odd as hell, was expecting that if there was an adaption/forced adjustment somewhere, the difference in value would be constant, '038mbar' over atomsphere, would expect when MAP is unplugged it to drop to 038, and not 049. Might have some corrosion in ECU, took top panel off it and looks clean but lower panel very well glued on, don't want to damage board trying to get it out at this stage.
When the MAP sensor is unplugged it drops from 138mbar, to 049mbar which is odd as hell, was expecting that if there was an adaption/forced adjustment somewhere, the difference in value would be constant, '038mbar' over atomsphere, would expect when MAP is unplugged it to drop to 038, and not 049. Might have some corrosion in ECU, took top panel off it and looks clean but lower panel very well glued on, don't want to damage board trying to get it out at this stage.
Thread Starter
Newbie
Joined: Sep 2020
Posts: 5
Likes: 0
w203 220 CDI
Well, looks like ECU is the issue.
Star didn't tell us anything we didn't already know in this case.
Engine off, ignition on, sensor wire cut from back of ecu plug for both MAP + MAF. The MAP is reading +0.45v, and the MAF is reading +0.2v approx. So inside ECU something is causing a short or leakage onto those two terminals or one of their internal components. Every other parameter is spot on, have another w203 here but can't change ECU over to see if it works as they are coded in a few ways I think.
Need a sensible ECU repair person in the UK now, yeay.
Star didn't tell us anything we didn't already know in this case.
Engine off, ignition on, sensor wire cut from back of ecu plug for both MAP + MAF. The MAP is reading +0.45v, and the MAF is reading +0.2v approx. So inside ECU something is causing a short or leakage onto those two terminals or one of their internal components. Every other parameter is spot on, have another w203 here but can't change ECU over to see if it works as they are coded in a few ways I think.
Need a sensible ECU repair person in the UK now, yeay.
