Vauxhall Astra GTC 2.0 CDTI - Intermittent MAF Issue (not a normal MAF problem)

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Fri 24 May 2019 11:05
Vauxhall Astra GTC 2.0 CDTI - Intermittent MAF Issue (not a normal MAF problem) - Terry Webster

I have a Vauxhall Astra GTC 2. CDTI and it has developed a rather strange fault. Usually when a MAF fails, reading the wrong reading etc you replace it or clean it as it causes poor idle etc. However my issue is something I cannot find anything on.

One day the engine light came on, code reader, P101 P113 - Air Flow Sensor, so I checked the live MAF reading which showed no reading. So I unplugged the MAF and plugged it back in, and my live diagnostics showed it reading air flow fine again, then it would stop reading again, sometimes moments later, sometimes after a few days. I bought a new Bosch MAF thinking there's a fault with the old one, nope, same issue, so tried another new MAF after a couple of months thinking maybe the new one was faulty. Nope, same problem, works for a short while after being unplugged and plugged back in, just to stop working again.

Is anyone able to shed some light on this or experienced it before?

Thanks

Edited by Terry Webster on 24/05/2019 at 11:31

Reply | Report as offensive | Link
Fri 24 May 2019 12:29
Vauxhall Astra GTC 2.0 CDTI - Intermittent MAF Issue (not a normal MAF problem) - RT

Check all the connections into the ECU - don't know if they still do by Opel/Vauxhall used to mount the ECU directly on the engine - the vibrations eventually caused fatigue to the soldered connections, specifically the earth return connections.

Reply | Report as offensive | Link
Fri 24 May 2019 12:46
Vauxhall Astra GTC 2.0 CDTI - Intermittent MAF Issue (not a normal MAF problem) - elekie&a/c doctor
I would say the fault code for the Maf sensor is the result of another problem. Possibly an Egr valve issue .
Reply | Report as offensive | Link
Fri 24 May 2019 13:03
Vauxhall Astra GTC 2.0 CDTI - Intermittent MAF Issue (not a normal MAF problem) - Terry Webster

I've just done a quick google and it looks like the ECU is in the engine bay near the battery, but not directly on the engine. It seems like an electrial fault to me as it is intermittent, I'll have a good check over the wiring and particularly the ground wiring. Thanks

Reply | Report as offensive | Link
Fri 24 May 2019 20:28
Vauxhall Astra GTC 2.0 CDTI - Intermittent MAF Issue (not a normal MAF problem) - 3uga

You should check current suply and then check if you have signal to the ecu.
Check for a wiring diagram of the maf so you know what to measure and where.
Most likely it is a bad conection. You shoud get some test needles to put in maf conection so you can measure the voltage when the problem apears.
Keep in mind that the problem may apear to be related to the maf while it could be entirely something else.

Have you checked for any cracked hoses between the maf and turbo? False air intake could be your problem? You could have a disconected engine breather pipe or a small hose.

Edited by 3uga on 24/05/2019 at 20:30

Reply | Report as offensive | Link