Vehicle MAP sensor adjustment

Thread Starter

noelywire2030

Joined Apr 18, 2022
1
Hi. My car is going into limp mode as my turbo isn't putting out enough pressure. I don't mind that it's not boosting 100% but limp mode is a pain. I believe atmospheric pressure is about 2.5v on the map sensor. Full boost is about 5v. My car is boosting to about 4v. The map sensor has 3 pins. Ground, 5v and signal. I want to pull up the signal from 4v to 5v at full boost. But not alter the min volt voltage. How do I do it? Thanks.
 

LowQCab

Joined Nov 6, 2012
2,182
Don't do it ..........

Find out why You are getting a Trouble-Code instead of guessing.
Attach a proper Scan-Tool to the Diagnostic-Connector at an Auto-Parts-Store, it's free of charge.

Turbo-Boost may be turned down, or even not allowed,
when certain Diagnostic-Codes have been set in the Computer.

If You mess with the MAP-Sensor-Voltage your Car will run poorly guaranteed.
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ThePanMan

Joined Mar 13, 2020
436
Wouldn't recommend it. If you alter the reading up by one volt what will happen if suddenly the problem fixes itself? Now your computer is getting hit with 6 volts. I gotta say I don't think the computer will like that very much. A few dollars to fix your problem could result in hundreds of dollars in repair bills. Possibly even a grand or more.

Like @LowQCab said -
Find out why You are getting a Trouble-Code instead of guessing.
In other words, fully diagnose the problem before you start fixing or adjusting things. It's nearly always a down hill slide on the ice. Once you're going down - there's nothing to stop you but the crash at the end when you have a pile of mess to clean up.
 

shortbus

Joined Sep 30, 2009
9,449
Attach a proper Scan-Tool to the Diagnostic-Connector at an Auto-Parts-Store, it's free of charge.
That may be so where you live, but around here they only use a code reader. A scan tool is a completly different thing, and fairly expensive compared to a code reader.

I just bought a scan tool a Launch 431 Pros Mini, and it was ~$700 compared to my latest code reader that was less than $100. But the scan tool can do so much more and having 7 grand kids of driving age it will end up saving money in the long run on repairs to their cars.
 

GetDeviceInfo

Joined Jun 7, 2009
2,101
Hi. My car is going into limp mode as my turbo isn't putting out enough pressure. I don't mind that it's not boosting 100% but limp mode is a pain. I believe atmospheric pressure is about 2.5v on the map sensor. Full boost is about 5v. My car is boosting to about 4v. The map sensor has 3 pins. Ground, 5v and signal. I want to pull up the signal from 4v to 5v at full boost. But not alter the min volt voltage. How do I do it? Thanks.
it would likely stay in limp mode when the oxygen senor couldn't be satisfied. Is your wastegate leaking?
 
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