Technical P0236 1.4T Multi Air

[AGrant]

Just putting this out there in case someone happens to have the same issue on their Fiat 500x 1.4 Turbo and finds this on a search.

I've been battling a P0236 error within the ECU on and off for over a year, where the turbo would suddenly stop working, but an ignition on and off, would make it work again, so points to it not being a turbo issue, but somewhere else.

I posted a question on the 500x FB group asking about when people were seeing boost (as mine was coming in around 3000rpm and only in 3rd gear onwards), the answers were that they were getting boost in all gears and from 2000rpm onwards. Someone made a comment it could be a loose wastegate actuator arm and put a video to a YouTube video about it (https://www.youtube.com/watch?v=8hOzN6vzkZo)

This was the issue and took all of about 20 mins to do the necessary changes and the car drives like normal again and no more codes being thrown in the ECU. Happy days

 

[varesecrazy]

Glad you got to the bottom of it

The way you said 'only in the upper gears'

I was suspecting a management issue..

But presume its effect..or lack of it..
Is not noticed at lower speeds

 

[arekp]

I've had this twice, 2 years apart. Each time was due to a faulty MAF sensor. Replaced the sensor, and back to normal.

BOSCH 15-05-30 2 E 18
0 281 006 028

 

[arekp]

It was MAP sensor, not MAF thanks @justdefend89

 

[M6rk]

Just wanted to say a big thank you to the OP for posting his issue and the resolution.

If anyone is suffering with cruise control issues where it will get disabled and not be able to be re-enabled until a power cycle then scan for codes. Mine was showing a code of P0236 and then it chucked the EML on.

We had only just bought the car so I feared I might have bought a lemon. It wasn't boosting very well at all but as I hadn't driven any other 500x's I just figured it was slow.

I adjusted the wastegate actuator arm and added about 6 mm of preload and that fixed the issue. Cruise control is happy and the car feels a lot quicker! I think I wasn't getting hardly any boost at all.

Hopefully this will help other people as well

Thank you all

 

[s130]

Well the other day I had the same boost issue. No EML. Car boost gauge will raise to two bars and stubbornly hover there till RPM went to around 2500 rpm and then climb to full deflection under full throttle.

500X - 1.4 - 2015 at a low mileage of 30,787

o removed heat shield - NOTE - the lower two nuts were well soaked with GAS-PLUS end then jiggled/vibrated off with a Ryobi electric ratchet wrench. You could to the same with a low torque air wrench (NOT impact drive). Alternative is to tap-tap-tap-tap. If you use force the studs will shear off and you are then stuffed. Last resort is to bend the heat shield up and wedge in raised position.

o checked the waste gate actuator rod and got easy movement of the rod on the flapper arm

o carefully removed circlip. put an cloth beneath and slim fish algae magnet alongside and partly below as added security for dropping the circlip

o waste gate rod slid off with no effort indicating no preload

o undid rod eye locking nut and counted 27 HALF turns to get actuator eye off the road - cleaned the road threads and fully greased with high temp. molly grease. also put grease into the road end eye threads

o put rod end eye back on counting 27 half turns and checked it was in the same neutral position thus confirming stability in what was originally found

o now wound rod eye on a further 8 half turns which is 4mm. nipped up lock nut

o moly greased rod end eye and flapper spindle/shaft. moly greased all nuts, studs and bolts

o roadtest. Brilliant. HUGE difference.

As seems to be reported elsewhere on the web the turbo waste gate rods were originally set with zero or minimal preload. Also age / wear in eye or flapper closure surface seems to creep in over time thus resulting in the issue as the car ages.

I've seen/heard people putting 4mm, 6mm, even 8mm of preload. I chose 4mm as this should be sufficient to keep the flapper fully closed and not risk overboost pressures. If required I can put another 2mm (4 half turns) on.

 

[Xenotime]

I did all these with preload. I even replaced waste gate actuator, turbo it self, map
Sensors and N75. No obvious air leak. Please help…