CEL P0351 Ignition Coil "A" Primary Control Circuit/Open

[milanojess]

i got this yesterday and came to this thread as result of searching. I am ordering an ignition coil as result.

A quick summary of this thread is that ( in no particular order )

1. cyl1 high temp due proximity to exhaust header
2. wrap with insulator improves but not necessary eliminate issue
3. one person mentioned battery replacement
4. one quoted dealer that problem with fuel pump could induce the code.
5. some suggested to find way to bring some cooling into this area
6. harness might be culprit and theres a doc to test it referenced in this thread.

But in general people just replace the coil.

Mine is 2013, 28k miles, tracked a few times, never an issue at track though, but happened a few times on the road ( 2 or 3 now ), usually stepping on the gas doing a 2nd or 3rd gear pull to pass slow moving obstacles hugging left lane... I think at track I am usually moving at pace and there are better cooling happening there, but sitting in traffic trapped heat and IC pops when pushed.

if code comes back in a few month, i'll do a new battery ( it's around 7 years old now anyways), i'll need to search for a small/lightweight lithium thing that should deliver the punch better than the sealed liquid glass mat thing.

[DarkSunrise]

Originally Posted by strat61caster

Just replace the packs and enjoy many miles of trouble free motoring before they fail again, time will tell if the updated parts are better.

I feel like they degrade over time and maybe only certain positions bring out the failure, but I'm an outlier with #1 and #2 failing on mine.

You're not alone lol! Replaced my #1 coil last weekend (3rd time - 20k mi, 27k mi, 40k mi). This time I tried adding DEI gold tape on #1.

Today I got #2 for the first time (41k mi). Will DEI wrap #2 when I replace it.

I added the Verus DI ECU and fuel rail brackets recently after someone on this thread said the thinner brackets helped dissipate heat. We'll see if the tape and brackets help.

I'm on a fresh battery (replaced April 2020), so I don't think that's a contributing factor. I think the damage happens after hard usage when the car sits. The heat pouring off the exhaust and engine cooks the coilpacks.

[Ragin Gti]

There’s an updated wiring harness and coils that fixes these codes. For ‘13-‘14, the ‘15 and up have the new harness and coils. Subaru TSB # 07-120-17R


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[RickyRacer]

anyone here replace their wiring harness on a 13/14 to the MY15+ harness?


Wondering if it's something i can DIY... need to switch coil pack #3... got the code

[sato]

Originally Posted by RickyRacer

anyone here replace their wiring harness on a 13/14 to the MY15+ harness?


Wondering if it's something i can DIY... need to switch coil pack #3... got the code

Same question from me. Anybody?

[blsfrs]

https://www.ft86club.com/forums/show...=145414&page=2


Some info here.

[sato]

I read about some adapters to use newer coils (https://www.ftspeed.com/part/coil-ad...t#.YaFDDdDMKUk) but no information regarding if we can actually use a 2015+ wiring harness (complete engine harness btw) on our models.

The Subaru TSB 07-120-17R states different P/Ns for the 2013 and 2014 wiring harnesses, but no additional years are covered under that TSB. I can't find any regarding FR-S for that matter. Reason could make us believe 2015 wiring harnesses might work, but I'm not sure if I'm willing to find out it doesn't work / still have to purchase a new one.

As @whataboutbob stated back in 2015 (https://www.ft86club.com/forums/show...ighlight=P0353), SU003-04463 was the Toyota updated part per TSB 0013-0014. However, it seems to be a 2013 P/N only, same as the SU00304559 supersession. There is no supersession P/N for the 2014 model, or link between the 2013 MY wiring and recent update. Still, the SU00304750 fits the 2013 model.

This is the info for the Toyota P/Ns I found today (26-NOV-2021):

SU00304750 (2013, 2014), SU00305266 (2015) ~$400
SU00307784 (2017+) ~$1500!!!

Still unsure how they compare with the BRZ P/Ns, mentioned in their 2017 TSB.

PS Forgot to update, but it seems that the 2015 part (SU00305266) DOES fit the 2014 model, but might be only because they are ZN6C or ZN6D models (mine is ZN6B)