184 FR Error code 00531 with Carista


Apr 21, 2005
Can anyone shed any light what this error could be caused by?

Just scanned it on Carista and I get 00531 ( Mass air flow sensor voltage) if I clear it the fault reappears as it can not be cleared.

the car is boosting fine, no EML and no limp mode. I looked at the MAF physically all connections look ok from just looking at the them.

Thanks in advance


Active Member
Nov 19, 2019
Hello there,

I think the error code 00531 (air flow meter reference voltage)

053 from the above code I think means supply voltage too low.

Could be a poor weak connection even though the contacts in the connection plug look ok, try spraying some WD40 into the connection plug, also check with a multimeter if you have 12volts at the plug for the main power wire just to be sure.
The signal/trigger wire you should have I think 5volts.
The dash warning light doesn't always come on for connection errors, it depends how much the sensor is affected, and if the ECU is constantly receiving out of range readings.

I think you'll have 3 wire's on the connection plug, power, earth, and signal, but there could be more than 3 wire's depending on model.
Using a multimeter set to 20volts with the cars ignition switched on, put black test lead onto black or brown earth wire, then red test lead to power wire, you should see like I say 12volts.
If you don't know which wire is which, then put the black test lead to an earth point on the body, or just put it on the battery earth, this way you'll be able to test for 12volts and 5volts from the connection plug, for main power feed and signal.
But also you'll need to ideally check you have a good earth from the connection plug, so take the black test lead off battery terminal earth, and probe it into the one wire left you haven't tested, which in theory will be the earth wire.
If the wiring seams ok then could possibly be a weak sensor.

Most modern cars now have two air intake sensors, (1)- mass air flow sensor) (2)- mass air pressure sensor) so if one is playing up the engine will still run, depending on how the one sensor has failed ?
The two above sensors work together passing through the ECU, it's possible the mass air flow sensor can have more then 3 wire's.

Mass air flow sensor = measures rate of air flow entering throttle body.

Mass air pressure sensor = measures overall mass volume of air inside inlet manifold.

The only thing about the cheaper scan tools is they can't always clear the fault code, and yes they can show you an error code, but the proper more detailed information you get from the more expensive scan tool, normally give you the VAG error code starting with the letter P
Using the cheaper scan tools like the Carista, it's best to check the conversion chart from the basic error code to the more detailed OBD2 where error codes start with the letter P

OBD2 Code P0651 is related to voltage difference, I think the mas air flow sensor has various resistance readings depending on how much air flow is passed over sensor, plus the signal voltage can fluctuate from 5volts + or -
So if the voltage was weak or none at all in most cases this would bring on a dash warning light.

OBD2 code P0101 fault will mass air flow sensor, again this error code will normally bring on the dash warning light.

Other than that it's to take your car to your local trusted garage, and see what error code/s they'll find on their more detailed scan tool.

Hope this helps


Active Member
Feb 16, 2019
Carista isn’t reliable for error codes in my opinion. Case in point, I’ve emailed them about this very code on my car. Here’s their response ...

Hello, thank you for sharing this information with us. We have checked it and unfortunately it seems that we have a mistake in the codes that we have shown you for your car.

“00531 is actually Footwell Illumination Electrical Failure, so you shouldn't worry, it's not about the MAF sensor
263442 is Siren / Alarm Horn for Anti-Theft Alarm System (No Release by Immobilizer)

I'm very sorry about the caused confusion.”


Active Member
Feb 16, 2019
Disappointing that they still haven’t fixed this. I’ve been in the beta for months and have given up reporting bugs now. They never get fixed.
Listers, parts supplier