I think I just caused my MAF (Mass Air Flow Sensor) to fail. I was just fixing a EVAP issue with my purge valve (fault wiring issue) and finally corrected the issue and was doing my drive cycles so my codes would clear in my ECU. I'm past due for my state inspection so I had to do my drive cycles at night to avoid the police. Then my Dad came up with this good idea to get all four wheels off the ground at my house and do my drive cycles that way. Well the EVAP monitor on my scanner finally completed with out throwing a code (p0444) which is great but it threw code p0102 Mass Air Flow low circuit voltage and has been doing so every since.

My common sense is telling me, this is not a legitimate code based on normal driving conditions. Since my car was off the ground my engine didn't bring in the predetermined airflow for the speed my odometer read.

My question is how can I get rid of this code to do my inspection? Will more drive cycles on the ground clear the code or do I have to clear that code which means that I have to do my drive cycles all over again? Does any know if I may have damaged the speed sensors or TC system or if that was a bad idea.

Please help....I'm trying to keep the Rover Spirit but this truck is sensitive and sometimes hard to figure out. Thanks a bunch for reading!

 

Your reasoning sounds reasonable. And, if it is correct, it seems you will need to do the drive cycles on the ground and moving air through the system with the correct force.

 

This is a quote directly from the Rave Workshop Manuel that tell how the car saw that there was a problem which threw the code. Can anybody tell me what this means so maybe I can drive long enough to make this code go away. This will be a big help. Do you thing MS means minutes, and to me 200 rev/min can be reached at idle. So could I just idle my car to meet the need and the light go off?






















There are two types of MAF sensor diagnostic check:


l The MAF sensor signal is less than the minimum threshold for specific speed range – the engine must have



exceeded 200 rev/min for longer than 300 ms and remain above 400 rev/min. The signal must be less than the

threshold mapped against engine speed for longer than 500 ms.


l The MAF sensor signal is greater than the maximum threshold for specific speed range – the engine must have



exceeded 200 rev/min for longer than 10 ms. The signal must be greater than the threshold mapped against

engine speed for longer than 300 ms.

If the MAF sensor fails the following fault codes will be produced and can be retrieved by TestBook:


P code J2012 description Land Rover description



P0102 Mass or volume air flow low input MAF signal < minimum threshold, which is speed

dependent

P0103 Mass or volume air flow circuit high input MAF signal > maximum threshold, which is speed

 

ms=millisecond

1000 ms = 1 second.

300 ms = roughly 1/3 of a second

As far as the other questions, I'll let the more qualified help answer that.

My opinion is that since the MAF code happened while on the blocks, I'd try off the blocks and see if it goes away. But again, I'll leave it up to those who know better.