Technical Loss of power and P0401 & P0236 Diagnostic codes - Multijet 1.3 Diesel

[NashRaytei]

So I've been driving a 2006 Fiat Punto Grande 1.3 Multijet given to me as my first car by a family friend.

It's done about 180k+ miles and has been a good workhorse.

However in the last 6 months it's been low on power; I've managed to get it running better by using higher revs on lower gears, and doing engine restarts after it warms up a bit, but it's not very consistent. I've been doing long runs with it and using more expensive fuel + redx which has done it some good, but hasn't fixed the problems.

I've had the engine error codes checked and i get P0401 and P0236.
I'm not exactly sure what i can do to try and alleviate these problems and any advice would be very welcome.

 

[nikrox]

Just 'googled' the codes...egr valve and turbo boost sensor ..search the forum it might help..

 

[Bernievarian]

Hi Who ??

and welcome on board …

what version of engine is it ? 75 or 90 hp ??

Anyway, @ 180 k+ miles, the EGR and the MAP probably needs cleaning …

BRs, Bernie

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[AndyRKett]

I've had the engine error codes checked and i get P0401 and P0236.
I'm not exactly sure what i can do to try and alleviate these problems and any advice would be very welcome.

Important question, did you clear the codes and then take it for a drive, then recheck.

Sometimes codes can be stored for years if the car has never had them cleared in the past.

If the car is on 180k Miles, it maybe due a turbo, it may have a sticking wastegate or just be very choked up with carbon and gunk.

Egr valve shouldn’t really cause major issues unless the car goes into limp mode.

 

[NashRaytei]

Tried clearing the codes and instantly they came back, wouldn't clear.

I'm not sure which bhp version the engine is.

The car goes into what i think is a limp mode when starting normally, not wanting to rev very high, like maximum 3500-4000 in 2nd and 3rd, this would continue until i do the next step. The way i get around this is by restarting the engine a couple of times after letting it warm up a bit. After this i get a decent pull and amount of power; but i think it's still missing some.

EDIT: The other question would be where is the MAP sensor on the engine? I've been googling around and i can't seem to find anything for the 2006 model.

 

[Bernievarian]

The MAP sensor is at the back of the intake manifold, close to the firewall, set with one screw (torx). You have to lift the plastic clip before pulling off the connector ! Once removed DO NOT try to clean it with sharp object, you could damage the NTC ! Carb cleaner works perfect for this purpose, hot soapy water as well …
You haven't told the engine version !? They Don't use the same approach with the turbo …

BRs, Bernie

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[NashRaytei]

You haven't told the engine version !? They Don't use the same approach with the turbo …

Just went looking, I've got the 90 hp version.

 

[Bernievarian]

Ok, in 90hp version the turbo uses variable vanes technology (variable geometry) vs wastegate in the 75hp.

Check that the actuator's link is still connected to the vanes' lever.
Check that the vanes are Moving: you can move the actuator's link by hand.
Check integrity (cracks) fo pipes coming to and from the actuator's electrovalve
Disconnect incoming pipe @ electrovanne and check for vacuum (engine running)
If no vacuum, crawl Under the car and check for crack in pipes to and from the accumulator (next to the starter motor)
If vacuum circuit is ok you need to check the signal that comes to the électrovalves: as it's a PWM you'll need a o'scope :-( … in theory. Alternatively you can hook a 21 watts bulb (brakes) instead of the electrovalve: it should brigth differently according to the PWM: off (or almost) at idling and bright at full (engine) speed.
If all above (easy) checkings are ok, you'll need to investigate further !

Let us know how you get on …

BRs, Bernie

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[Appierre1]

Did all that Bernie said and still had same problem on GP 1.3 90bhp, of going into limp mode. EGR had been cleaned so changed Mass Airflow sensor (one on front rhs of engine cover before filter) no change. Unfortunately I changed it back to the original one....Next changed MAP sensor no change. Then changed both...fixed. Both MAP and MAF sensors where defective. I also made sure the plastic tubing from the front inlet through the MAF into the engine cover where a tight fit and well secured so that particularly the fit after the MAF did not leak. Car has been brilliant for last 9 months since fix.

 

[Bernievarian]

Thanks for sharing your experience on that one Appiere !! Did you get the same codes as the OP had ??

BRs, Bernie

 

[Appierre1]

Thanks for sharing your experience on that one Appiere !! Did you get the same codes as the OP had ??

BRs, Bernie

Yes. I did. All exactly as you described. Thanks

 

[Mw99]

Hi there
I have a 1.3 multimeter 90bhp and get the same issue every 18 months, engine mgmt light comes on and it goes into limp mode.
Solution is some Wynns EGR cleaner and fuel additive turbo cleaner, approx £15 from various motor factors.
The instructions are fairly straight forward, it takes around 10-15 mins.
Then some "easing" on the wastegate with pliers or a flat screwdriver to loosen off and everything should be back to normal. There are plenty of youtube videos for loosening the Watergate and the erg cleaning process.
Restart and the engine mgmt light will be off and the engine revving Freely at full power again.
Hope this helps

 

[Bernievarian]

.
Then some "easing" on the wastegate with pliers or a flat screwdriver to loosen off and everything should be back to normal.

There is no such wastegate valve on the 90hp version ! Fiat uses VVT (variable vanes technology) on these versions vs wastegate on the 75hp ...

There MUST be a reason why your car clogs the turbo moving vanes and the EGR every 18 months; door to door delivery, frequent starts, city drive only, short trips, rarely getting to temp, thermostat (partly) open etc.

BRs, Bernie

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