Technical Help! Fault Code: P1524-79 Spark Plug Anti Fouling Diagnosis - Mechancical Linkage failure

[BarryT01]

Hi all. I'm new to the forum, and seeking some advice please.

I've owned a 2011 Fiat 500 Twinair Lounge for about 3 years, and it's been nothing but trouble. The latest issue is the above fault code, which triggers the Check Engine light, and a dramatic reduction in power.

I've researched it online and it seems others have had P1524 (relating to low oil pressure), but very few have had P1524-79.

The garage that diagnosed the code for me suggested it may have the wrong oil, so I've done an oil and filter change myself using Petronas 0w30 7000E and a Bosch filter cartridge. I also changed the spark plugs for NGK 97168 Laser Iridium. I noted these are exactly what was already fitted, so was a like-for-like change. The old plugs looked well used, but no obvious anomalies.

I ran the engine for about 30 seconds to allow the new oil to circulate and find its level, topped it up and then took it for a quick test drive. Less than half a mile later it happened again; Check Engine light, reduction in power.

My OBDII code reader doesn't connect to the car (for some unknown reason) so I can't check it's the same code, but I'm assuming it is.

Any thoughts or suggestions would be greatly appreciated!

 

[John202020]

Hi seems not too many suggestions so far, not got this type but
Given the age of the car, has it suffered from the rear hatch wiring failure issue and or been fixed?
Twin air specific have you cleaned or replaced this oil filter https://www.shop4parts.co.uk/?name=store&op=Product&ProdID=21979

 

[BarryT01]

Hi seems not too many suggestions so far, not got this type but
Given the age of the car, has it suffered from the rear hatch wiring failure issue and or been fixed?
Twin air specific have you cleaned or replaced this oil filter https://www.shop4parts.co.uk/?name=store&op=Product&ProdID=21979

Hi. Thanks for responding.
I'm not aware of the rear hatch wiring issue you mention. It's not had it fixed during my ownership. What's the issue?
I also wasn't aware of the twinair oil filter you linked to. I'll have to look into that.
Thanks

 

[jrkitching]

I'm not aware of the rear hatch wiring issue you mention. It's not had it fixed during my ownership. What's the issue?

It's a design fault. Opening and closing the rear hatch bends the cables running between them through a sharp angle, and the type of wire used by Fiat isn't capable of being repeatedly flexed in this way. After a few years, the insulation splits and/or individual wires in the harness break completely. Depending on which cables break, various parts stop working and/or trigger error messages, and if the wrong wires actually touch, a resulting stray electrical feed is capable of damaging pretty much any electrical module on the car.

The only permanent fix is to patch all the wires in the loom at that point with a type of cable capable of withstanding the repeated flexing. It's a very common issue, and repair kits are available.

That said, the hatch wiring fault may not be the cause of your problem. There are two components in the induction circuit which are known to give trouble at higher mileages (>40k or so). The intake system (aka the uniair module) is prone to wear, after which the inlet valve events don't work properly, leading to power loss and eventially putting on the EML. Also wear in the turbocharger is quite frequently reported, with similar results; again after perhaps >40k miles, depending a lot on how the car has been driven.

It pains me to say this, but from all the posts I've seen on this forum, a 10+yr old TwinAir, especially one with several previous owners, is basically a liability waiting to happen.

Take a look at this recent thread, especially the link in post #5

 

[BarryT01]

It's a design fault. Opening and closing the rear hatch bends the cables running between them through a sharp angle, and the type of wire used by Fiat isn't capable of being repeatedly flexed in this way. After a few years, the insulation splits and/or individual wires in the harness break completely. Depending on which cables break, various parts stop working and/or trigger error messages, and if th wrong wires actually touch, a resulting stray electrical feed is capable of damaging pretty much any electrical module on the car.

The only permanent fix is to patch all the wires in the loom at that point with a type of cable capable of withstanding the repeated flexing. It's a very common issue, and repair kits are available.

That said, the hatch wiring fault may not be the cause of your problem. There are two components in the induction circuit which are known to give trouble at higher mileages (>40k or so). The intake system (aka the uniair module) is prone to wear, after which the inlet valve events don't work properly, leading to power loss and eventially putting on the EML. Also wear in the turbocharger is quite frequently reported, with similar results; again after perhaps >40k miles, depending a lot on how the car has been driven.

It pains me to say this, but from all the posts I've seen on this forum, a 10+yr old TwinAir, especially one with several previous owners, is basically a liability waiting to happen.

Take a look at this recent thread, especially the link in post #5

Useful info, gratefully received. Thank you.

 

[BarryT01]

OK, I ordered up a set of box spanners from Amazon (£9.25 for a set of 8 dual sized box spanners, including same day delivery!) and this morning I removed and inspected the twinair oil strainer. It looks pristine, almost suspiciously so considering the car has done 49,000 miles! There were some traces of old engine oil around the threads, but only the lovely clean oil in and on the gauze strainer itself (I did an oil change 3 days ago and have only driven about a mile since then).

So that's not my issue, but at least I know it's clean and not clogged.

I'll have a look at the wiring to the rear tailgate at the weekend. That might explain some of the electrical gremlins my car has suffered from, but given its relatively low mileage I'm not sure I'll find a problem there either.

Still open to any other suggestions! Thanks.

 

[John202020]

I'll have a look at the wiring to the rear tailgate at the weekend. That might explain some of the electrical gremlins my car has suffered from, but given its relatively low mileage I'm not sure I'll find a problem there either.

Age not miles is the factor with the wiring and the number of times the boot lid opened especially when very cold