T5.1 maf sensor implausible signal

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   Hi. I’m new to the forum and new to owning a t5 and looking for somewhere to start looking for a mysterious fault I seem to have!
A few weeks ago I got my foot on the t5 ladder with a 2011 140 6spd 4motion. Lovely van but shortly after picking up the eml came on so had my mate plug it it in for me and it displayed p010100(implausible signal from maf sensor). Maf looked new and on contacting previous owner he confirmed it had recently had one. Have since had new air filter, another new genuine maf sensor, checked all obvious pipes from air box to turbo and the plastic one from that to the inlet manifold and wires to the plug and as far as I can see them into the loom. I then had the fuel system terraclean done and he tested the pressure either side of the dpf and said it was clear and functioning well. It did improve slightly but light has since come on again showing the same fault! Van also feels quite flat at low revs. 
Any pointers would be very gratefully recived as I’m approaching the end of my tether and starting to wish I had my old transit back!  

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Boots79 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Jan 19 Location: Dorset Status: Offline Points: 4	Post Options Post Reply Quote Boots79 Report Post Thanks(0) Quote Reply Topic: T5.1 maf sensor implausible signal Posted: 20 Jan 19 at 18:54
	Hi. I’m new to the forum and new to owning a t5 and looking for somewhere to start looking for a mysterious fault I seem to have! A few weeks ago I got my foot on the t5 ladder with a 2011 140 6spd 4motion. Lovely van but shortly after picking up the eml came on so had my mate plug it it in for me and it displayed p010100(implausible signal from maf sensor). Maf looked new and on contacting previous owner he confirmed it had recently had one. Have since had new air filter, another new genuine maf sensor, checked all obvious pipes from air box to turbo and the plastic one from that to the inlet manifold and wires to the plug and as far as I can see them into the loom. I then had the fuel system terraclean done and he tested the pressure either side of the dpf and said it was clear and functioning well. It did improve slightly but light has since come on again showing the same fault! Van also feels quite flat at low revs. Any pointers would be very gratefully recived as I’m approaching the end of my tether and starting to wish I had my old transit back!

912 Members Profile Send Private Message Find Members Posts Add to Buddy List Yardie Joined: 13 Jun 16 Status: Offline Points: 268	Post Options Post Reply Quote 912 Report Post Thanks(0) Quote Reply Posted: 20 Jan 19 at 19:37
	Check the wiring to the maf, check voltage to and from it, wiring is a common issue

Boots79 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Jan 19 Location: Dorset Status: Offline Points: 4	Post Options Post Reply Quote Boots79 Report Post Thanks(0) Quote Reply Posted: 20 Jan 19 at 19:46
	Ok great thank you. What kinda thing should I be looking for? I guess it should Hal around 12 going in on one of the pins? Have checked the wires from the sensor as far as they disappear into the loom but couldn’t see anything obvious. Are there any common fault points you know of? Thanks for your reply!👍

T5 TDI Members Profile Send Private Message Find Members Posts Add to Buddy List Vanorak Joined: 05 Nov 05 Status: Offline Points: 3687	Post Options Post Reply Quote T5 TDI Report Post Thanks(0) Quote Reply Posted: 20 Jan 19 at 21:13
	Welcome!I don't have the pinout for the t5.1 someone else might know, but you will probably find a 12v pin, a 5v reference pin, an earth and a digital signal wire that responds to the cooling of the hot film in the MAF. Be very careful indeed when probing anything because if you accidentally short across any of the pins you can wreck the ECU. Don't forget that code can be caused by other things like restriction of the intake or blocked exhaust/DPF. You should see other fault codes for that but not necessarily. I'd start by making sure the correct signals are at the MAF plug. Good luck. Edit- Or a problem with the EGR valve (not unheard of on the CR engines!) If you can get it diagnostics you can see what the MAF is showing as actual airflow and compare that to the expected airflow live on the road. Edited by T5 TDI - 20 Jan 19 at 21:22
	2004 2.5 174

Boots79 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Jan 19 Location: Dorset Status: Offline Points: 4	Post Options Post Reply Quote Boots79 Report Post Thanks(0) Quote Reply Posted: 20 Jan 19 at 21:25
	Ok great thanks for the reply. I am hoping the possibility of dpf/exhaust blockage has been ruled out by the very helpful terraclean man. Will have an investigation tomorrow night and see what I can find! Thanks again