javier.abraham
Member +
Ok i just did the diagnostic...Codes 31 & 34 Came on....what now?
vaf Sensor Problem! help!!!
- Thread starter javier.abraham
- Start date
Ok i just did the diagnostic...Codes 31 & 34 Came on....what now?
javier.abraham
Member +
Yes, i disconnected and connected the MAP Sensor connector, then i took the EFI Fuse off for around 50 seconds, put it back on, got the car to running temperature and ran the diagnostic.
I disconected the one in the picture that's marked with an arrow.
javier.abraham
Member +
Around 12 PSI but i have an HKS FCD.
javier.abraham
Member +
Does anyone has an image of it actually connected to the ECU, thats not the diagram?
Also, what about the other problem lol im more concerned about the fuel consumption?
Texx
Super Moderator
Ideally you need to be in a situation where the ECU isn't detecting any faults before looking for other causes. Code 31 is indicating a fault in the MAP sensor circuit. It's either a wiring fault or the MAP sensor or FCD is faulty, however if it was a permanent open or short circuit you should expect the warning light to stay on. You need to solve this problem first, the ECU uses the MAP sensor signal to calculate fuel delivery and ignition correction, so it has the potential to affect fuel consumption.
javier.abraham
Member +
Ok, well i checked the wiring on the map sensor until it goes into the harness that goes thru the Fuel Injectors and into the car but after that i dont know where it goes. If i wanna check if it's the FCD, should i take it off or can i just put it on 12 and then try?
So yo are saying it's definatly not the Sensor marked in the circle?
corofin12345
Member +
have you any fueling mods??? if not turn off the fcd.. 12 is off.. 12psi is on the border of fuel cut.. turn down the boost a bit if you can
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javier.abraham
Member +
Yeah i have 255lph fuel pump, used to have 330cc Fuel Injectors but im back to the stock ones now,fuel pressure regulator set to 50psi right now.
corofin12345
Member +
your fpr is set right anyway... just try turning down the boost to .75 of a bar(11psi) and see if the problem i still there and turn off fcd. setting 12
javier.abraham
Member +
Will do that this afternoon, thanks mate, will get back here with the result, in the afternoon.
corofin12345
Member +
ok mate.. remember 2 reset the ecu again after turning down the boost then go for a spin and do a diagnostic again after
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javier.abraham
Member +
Will do. Do you happen to have MSN? If not, ill come back l8 with the result.
corofin12345
Member +
javier.abraham
Member +
i dont im afraid.. just post back on here sur
Ok mates. So i checked the FCD and on the diagrams all i see is 3 wires but my HKS FCD has 4. Black, Red & Yellow are connected where they are supposed to be but the other one is a light color, dont really know what color that it but its connected to a wire in the Harness that i got no clue what it does or where it comes from, so i took them apart and ran a diagnostic and i only had Code 31...I wasnt getting Code 34 anymore so i thought problem solved but i start the car and when i accelerate there is a point when im just starting to accelerate that the revs goes down and almost seems as if the car was about to turn off, i didnt took it out for a drive, was afraid to do it, so i put it back how it was, ran a diagnostic and still didnt got Code 34 so i took it out for a spin and it seems as when its reaching full boost it starts a misfire, when i came back ran another test and code 34 was back on. Don't know what to do.
Took out the sensor thats on the intake manifold, the one on the circle, here's how it looks, dont know if thats the problem or if its normal to be like it is, or is there a household item that i can use to clean it? If not, what should i clean it with?
javier.abraham
Member +
I didnt removed the FCD, i just removed the 4th wire that isnt on the diagram, ran the test and code 34 was gone, turn it on and it was being weird, revs would drop a little to the point where it seem it was gonna turn off and when i accelerated it felt like the engine was holding back, all this was done in Parking. After that i rejoined the wire that i disconnected, took the EFI fuse to reset the codes, put it back on and code 34 was still gone, after a drive i came back and ran the test and code 34 was ON again.
Texx
Super Moderator
Can you get a photo showing the wire connections of the FCD?
When installing a FCD, the PIM signal wire between the MAP sensor and ECU is cut. The white wire and yellow wire from the FCD are then connected to each end of the cut PIM signal wire. To be able to rule out the FCD causing code 31, you'll need to find the cut in the PIM signal wire by tracing the FCD yellow and white wires back to the vehicle wire harness and then join the PIM signal wire back together.
Can you get hold of another MAP sensor to try? If it's the MAP sensor that's causing code 31, then the easiest way to confirm it is by swapping for a known good MAP sensor.
Code 34 is indicating fuel cut has occurred, it's boost pressure related, you'll need to reduce boost pressure to stop it happening.
When installing a FCD, the PIM signal wire between the MAP sensor and ECU is cut. The white wire and yellow wire from the FCD are then connected to each end of the cut PIM signal wire. To be able to rule out the FCD causing code 31, you'll need to find the cut in the PIM signal wire by tracing the FCD yellow and white wires back to the vehicle wire harness and then join the PIM signal wire back together.
Can you get hold of another MAP sensor to try? If it's the MAP sensor that's causing code 31, then the easiest way to confirm it is by swapping for a known good MAP sensor.
Code 34 is indicating fuel cut has occurred, it's boost pressure related, you'll need to reduce boost pressure to stop it happening.