seemingly unsolvable g31 map sensor CEL
Thread Starter
AudiWorld Newcomer
Joined: Jun 2019
Posts: 3
Likes: 0
From: Wyoming
seemingly unsolvable g31 map sensor CEL
Hello all, thank you ahead of time for the help. I can't figure out this g31 map sensor for the life of me and it's driving my crazy. I've searched for months and while I have found many threads with people having what looks to be the same problem as me, I haven't found a single thread with someone figuring it out. I have taken it to a foreign auto repair shop and they were no help. Here is the information and codes:
16621/P0237/000567 - Manifold Pressure / Boost Sensor (G31): Signal too Low
17026/P0642/001602 - Sensor Reference Voltage A: Circuit: Low
000566 Manifold Pressure/Boost sensor (g31), Implausible Signal
I've checked the wiring to the MAP sensor and i'm getting 5.6 volts with the key on. It's supposed to be 5v right? I've tried replacing the map sensor. I've tried a different ECU and still no avail. I know it's an electrical issue because when i clear the codes they automatically come back when i turn the key on again. I've checked the wiring to the MAP sensor and it looks okay and tests out okay. The car was driving great, then CEL came on and it wouldn't boost anymore. I then jacked it up, took a look at some more wiring, specifically around the diverter valve and n75 valve, could not find anything out of the ordinary. Noticed some zip ties were on the n75 wiring pretty tight, so i removed the zip tie and CEL was gone. Drove it for 30 minutes and it came back again, car stopped boosting. Numerous people think it's a wiring issue but I can't figure it out. I've checked the fuses for the ECM and they are good. Checked the fuses and relays in the ECU box and they look good. Tried new diverter valve and n75 valve for the hell of it, didn't change anything.
What should i do next? my map sensor is definitely getting power.
The wiring loom to the map sensor also has some wires that run underneath the car. Anyone know where those go to? What's up with the sensor circuit low? Could it be another sensor that isn't getting power?
SO grateful for anyone who reads and takes the time to try and help me. I dont have the money to take it to a specialist audi shop right now. Thank you thank you thank you for the comments and help.
-Lucus
16621/P0237/000567 - Manifold Pressure / Boost Sensor (G31): Signal too Low
17026/P0642/001602 - Sensor Reference Voltage A: Circuit: Low
000566 Manifold Pressure/Boost sensor (g31), Implausible Signal
I've checked the wiring to the MAP sensor and i'm getting 5.6 volts with the key on. It's supposed to be 5v right? I've tried replacing the map sensor. I've tried a different ECU and still no avail. I know it's an electrical issue because when i clear the codes they automatically come back when i turn the key on again. I've checked the wiring to the MAP sensor and it looks okay and tests out okay. The car was driving great, then CEL came on and it wouldn't boost anymore. I then jacked it up, took a look at some more wiring, specifically around the diverter valve and n75 valve, could not find anything out of the ordinary. Noticed some zip ties were on the n75 wiring pretty tight, so i removed the zip tie and CEL was gone. Drove it for 30 minutes and it came back again, car stopped boosting. Numerous people think it's a wiring issue but I can't figure it out. I've checked the fuses for the ECM and they are good. Checked the fuses and relays in the ECU box and they look good. Tried new diverter valve and n75 valve for the hell of it, didn't change anything.
What should i do next? my map sensor is definitely getting power.
The wiring loom to the map sensor also has some wires that run underneath the car. Anyone know where those go to? What's up with the sensor circuit low? Could it be another sensor that isn't getting power?
SO grateful for anyone who reads and takes the time to try and help me. I dont have the money to take it to a specialist audi shop right now. Thank you thank you thank you for the comments and help.
-Lucus
AudiWorld Newcomer
Joined: May 2019
Posts: 4
Likes: 0
Hey Lucus,
My issue was a short in the wire loom. I pretty much removed the whole wire loom from the ECU and the engine. I checked every single wire till I found it. I hope you found your issue! You have two options to fix this issue. Be stubborn like me and take the loom apart till you find it. Or buy a used loom from my favorite Audi site, soon to be yours, Wolf Auto Parts. Here is the part number. ENGINE WIRING HARNESS 8E1971074GB It costs a pretty penny. $113 is the cheapest I saw it for this part. I am sure you are hands on, and either way you can handle. Sorry for the late reply. I will check back more often.
My issue was a short in the wire loom. I pretty much removed the whole wire loom from the ECU and the engine. I checked every single wire till I found it. I hope you found your issue! You have two options to fix this issue. Be stubborn like me and take the loom apart till you find it. Or buy a used loom from my favorite Audi site, soon to be yours, Wolf Auto Parts. Here is the part number. ENGINE WIRING HARNESS 8E1971074GB It costs a pretty penny. $113 is the cheapest I saw it for this part. I am sure you are hands on, and either way you can handle. Sorry for the late reply. I will check back more often.
Thread
Thread Starter
Forum
Replies
Last Post
Seabeast11
S4 / RS4 (B5 Platform) Discussion
8
Mar 10, 2007 05:06 PM
VorsprungTT
TT (Mk1) Discussion
2
Nov 28, 2006 03:16 PM
Swank4
S4 / RS4 (B5 Platform) Discussion
6
Dec 16, 2005 01:01 PM
