P0103 Peugeot boxer 2013

Frs2180 · Post by **Frs2180** » Wed Mar 04, 2020 6:27 pm

Hi all. Got a strange one at the min. Got a pug boxer with the 2.2 transit engine that's intermittently throwing a pending code for maf sensor high input. Watching live data pids. The maf is reading around 10 - 12 g/s at idle with EGR commanded in the low teens. Map also showing good figures. The fault seems to show it's self when driving. All the pids seem to read as expected. But suddenly the maf g/s will rise sharply to 659 g/s

I notice just before this happens the egr is commanded to 0 as if the ecu knows there's a fault coming. The maf has been changed with a known good spare but the fault remains. No scoping has been carried out yet as this is my first maf fault that hasn't been the sensor so need to look more in depth at the fault. Has anyone come across this kind of issue before ? Weirdly if you turn off and on again all is back to normal until it faults again.

Iver · Post by **Iver** » Thu Mar 05, 2020 11:39 pm

throwing a pending code for maf sensor high input. Watching live data pids. The maf is reading around 10 - 12 g/s at idle

The fault seems to show it's self when driving.

Perhaps scope it at time of fault looking for High Output as the code suggests. A high output could manifest as result of a poor ground.

Any Freeze Frame Data logged alongside the fault ?

Frs2180 · Post by **Frs2180** » Fri Mar 06, 2020 6:21 pm

Hello. I have scoped powers and grounds on various road tests put the vehicle is refusing to fault at the minute. The ground is ECU controlled and the 12v power is shared at a 5amp fuse with the clutch switch and reverse switch. It is possible I have disturbed the fault by moving the wiring but I have been careful to check everything I have moved for any wiring issues. It's going to be a case of driving whilst scoping the signal wire for a spike or glitch.

Technician · Post by **Technician** » Sat Mar 07, 2020 6:09 pm

Have you tried a frequency test?

Ign on = 683
Idling = 4133
3000 rpm = 6701

You could load test the supply wire to a maximum of 5A, and if that proves OK you can move on. Maf sensor could have a fault, and sometimes tapping it while running might show something up?

Iver · Post by **Iver** » Sat Mar 07, 2020 11:57 pm

It's going to be a case of driving whilst scoping the signal wire for a spike or glitch.

Yep. that could be a real good starting point.

Frs2180 · Post by **Frs2180** » Wed Mar 11, 2020 7:41 pm

I have not had chance to drop back on to this as we are very busy at the minute but I will check the frequency against the given figures for sure. The maf has been replaced with a known good from a transit but the fault still persisted. I have checked wiring diagrams and the 12v feed has a shared fuse with the clutch position and reverse switch. Although it's not setting a code for open circuit so dont suspect a wire braking down.

Technician · Post by **Technician** » Wed Mar 11, 2020 8:57 pm

If you disconnect the multi-plug from the maf sensor and load test the wire 12V (5 A) i think it was, then if it will hold that load depress the clutch pedal and put the gearbox in reverse, and if the fuse remains in tact, move on from there...

Frs2180 · Post by **Frs2180** » Wed Mar 11, 2020 9:15 pm

That's a good thought process. Thankyou. I had before on road test performed lots of clutch pedal pressing to see if it produced the fault but it didnt seem to change the reading. I will definitely try load testing with a bulb like you suggested.

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