P1102 - Focus Mk3.5 1.5 TDCI

[WellHuzzahHuzzah]

I bought a 2016 (a couple of weeks off 2017) Focus recently, and everything seemed fine until I drove through East Kilbride which has about 200 roundabouts in a row. When dropping gear to approach the roundabout, I got a service message appear and limp mode kicked in.

I've since found out that once the engine is up to temp, whenever I drop a gear which takes it above 3k revs, I get the P1102 error when checking with ForScan and limp mode kicks in. I turn it off and on again and it's back to normal until I drop a gear to take it around 3k revs again, and normally give it some gas. It doesn't happen every time incidentally, and it can take a few tries to get the error to come up.

So far I've cleaned the MAF and MAP then replaced the MAF, cleaned the EGR, checked as many pipes as I can and done a smoke test, replaced the fuel filter, and checked the air filter (which is pretty much new).

I did see a post where someone suggested checking the timing belt hasn't slipped (which I will check when I get a chance), but the car is running absolutely perfectly and pulls well up until the service comes on (the EML doesn't come on straight away). Does anyone have any suggestions of anything else I could check?

[WellHuzzahHuzzah]

Just to add to this - if the timing chain had slipped a tooth, would it be fairly obvious in the way the engine pulls?

[TomsFocus]

3 hours ago, WellHuzzahHuzzah said:

Just to add to this - if the timing chain had slipped a tooth, would it be fairly obvious in the way the engine pulls?

If you'd owned the car a while, yes.  As it may have been bought like this, not necessarily.

[Zen23]

I had the same problem. P1102, P003A, P02FA used to come up. Cleaned all sensors, help only for little while. Cleaned turbo boost control solenoid, tested vacuum line. Wanted to replace solenoid as seems like it's leaking little bit, but left it for now. I tried to check wiring from MAF but weather is not good at the moment. Forscan gives weird reading from MAF, 1.86g/s engine not running.  Multimeter gives strange reading as well. In the end got second hand MAF, reading is still the same but didn't have a problem so far. Strange problem. 

[Zen23]

Second hand MAF didn't fix it. And second hand turbo boost actuator  didn't help. Still got the same problem. Took it to Fofd, they were so sure it's a throttle body so they replaced it. They done smoke test as well. Problem came back 10 minutes later P1102, p003a, p02fa. Almost every time when car is fully warmed up and slowing down before roundabouts or costing down the hill.

It's seems like it could be anything, cambelt, turbo sticking, egr sticking, wiring or PCM.

[Stevethirt]

On 4/1/2024 at 11:28 AM, Zen23 said:

Second hand MAF didn't fix it. And second hand turbo boost actuator  didn't help. Still got the same problem. Took it to Fofd, they were so sure it's a throttle body so they replaced it. They done smoke test as well. Problem came back 10 minutes later P1102, p003a, p02fa. Almost every time when car is fully warmed up and slowing down before roundabouts or costing down the hill.

It's seems like it could be anything, cambelt, turbo sticking, egr sticking, wiring or PCM.

Sounds familiar I’m having the same problem, pretty much every time I slow down using engine braking I get a engine service now message.. code  is p1102 changed MAF sensor but it still hasn’t fixed it… I’ve had timing belt done clutch changed turbo replaced, but the problem was occurring well before that,  had it to a few garages now and they just can’t get to the bottom of the issue… I’ve noticed now that when I first start the car it does idle rough for about 15 seconds then settles back to about 975 revs.. also on the motorway around 60 mph it shudders like itcant breath properly then it settles again… so annoying 🤬🤬

[Zen23]

It's to early to say but now 3 days of driving without issue. I have to chech with forscan if maf still gives reading on not running engine. 

I have wiring diagram and test procedures from haynes. So I Disconnected the battery.  Cleaned 2 ground points under air filter, 1 on top of the strut. Removed wheel arch, it's 2 more ground points there. Removed PCM, it's under wheel arch in a front. I had to drill original bolts out, 4, to get PCM from protective case. On reassembly you will need 4 m6 65mm long bolts.

Checked continuity from MAF, MAP, Throttle body and Turbo vacuum solenoid position sensor on turbo. All checked out OK. MAP, Throttle body and turbo they all on the same circuit of power supply (4,8-5.2V and negative). So if it's dodgy connection on PCM all 3 items will fail or give wrong reading. 

Took PCM indoors and started cleaning all pins with 1200grit sandpaper and contact spray. Half of the little pins were covered in a white dust (could be corrosion).

On the second day reassembled everything. I noticed engine starts much quicker and power delivery is more dynamic. 

I just hope it's not because battery been disconnected and all electrics reset itself.