P0356 Error Code

[Dr. Amdahl]

Hi all, just started getting the engine check and VSC light. It's happened twice in a week so far (it resets itself after three or four restarts). I checked for codes which are logging as p0356 a faulty 'coil on plug' for what looks like the front right hand cylinder (Cylinder 6).

I have done a bit of research and have discovered that there are a whole range of prices for these things, the Lexus official one is quoted at £165 which seems a lot compared to the alternatives. I am also thinking it would be wise to replace all the plugs at the same time as the car's now done 55K Miles.

So, can anyone advise the best source for the coil and plugs? There seems to be a number of Toyota part numbers which are also confusing, don't mind paying for quality and longevity but from experience the (good) non originals are often just as reliable?

[ChrisKaye]

Hi!

If it were me, I would get some di-electric grease (or similar) and swap the no 6 coil with the next nearest/easiest to reach coil pack, cleaning the electrical connectors and putting a fair amount of grease on the connectors.

Run like this for a while and see if the fault code either goes away or follows the "suspect coil pack" to the cylinder you swapped it over with.

If the fault persists and definitely is the coil pack, it might be worth looking for a Denso equivalent (they are probably the OEM anyway)!

Sorry if this is teaching you to suck eggs, but is a fairly easy test to nail the fault, or clear it if the connections aren't great! :)

Chris

[Dr. Amdahl]

Not teaching me to suck eggs Chris! Appreciate the suggestions, have ordered some dielectric grease and will try that first - very good idea. Will keep you posted, many thanks.

[ColinBarber]

Unlike a misfire error code, that coil pack code is highly likely to be correct in that it is the coil pack that is faulty, but certainly worth just swapping it to make sure the fault code moves with the coil. These coil packs seems to be a weak point of the 350 engine.

As Chris has said I'd get a Denso unit. You can import them from RockAuto for around £70 including 2 day shipping and all taxes, but you may want to see if they are stocked in the UK so you don't have such high shipping costs. You can get the correct Denso plugs from Rock too.

[Dr. Amdahl]

OK so I ordered some di-electric grease and a new Denso coil from Rock Auto. In the meantime my curiosity got the better of me and I had a half hour spare so I decided to take a look at the coil. This has to be about the easiest part I've ever taken out of an engine! I removed it (takes about a minute) and gave the ECU connector and plug and the HT connector a good old spray with contact cleaner, the outside of it was coated in a brown dust (I assume these things must generate a healthy magnetic field when they're firing so they attract any fine oxidised metal dust) so I gave the whole thing a good wipe down. Put it all back together on Friday, no codes since despite a fair amount of driving. New coil will arrive from the States next week so it will go in the glovebox until I get a repeat.

[ChrisKaye]

Great news, might be worth cleaning the others up too when the grease turns up.

Thanks for the update! :)

[Dr. Amdahl]

New coil has arrived from Rock, total cost £40.72 including postage. Denso part number is 673-1309, even came with a free RockAuto fridge magnet and I didn't get charged any duty. Have been driving for over a week with no more error lights after using contact cleaner so it will go into my spares stash along with my wireless OBD dongle. Thanks Chris and Colin for your help as always.

[ChrisKaye]

Hi, anything less than £100 inc shipping doesn't attract duty.

Thanks for the update, I got the tip from the crazy youtube mechanic Scotty Kilmer...!

Di-Electric Grease:

Not sure, I'd let Scotty loose on my car but he certainly does motivate you to have a go at items you feel comfortable doing!

[ColinBarber]

Hi, anything less than £100 inc shipping doesn't attract duty.

But anything over £15 does attracts VAT.

[Dr. Amdahl]

Do you think I should hotfoot it up the road to Stansted and give FedEx their tenner? To be honest I think they owe me that for the rooftiles their so**ing great Jumbos have loosened thundering in to land at 3am 6inches above my house.

[ColinBarber]

I'm pointing out the VAT situation for other people's benefit. Be aware, and budget for, the full amount of tax due when importing parts, if you get charged less then it's a bonus.

[Dr. Amdahl]

I was only joking Colin, I guess I got lucky this time round. Still can't believe I saved £125 on one little part, makes you wonder how much of a markup other bits have. I guess we are subsidising the shiny big showrooms and the free coffee.

[Seafarer]

Hi all - had the VSC light and the engine symbol on intermittently. Local garage had a look today and came up with error p0355. Seem that this is on cylinder no. 5 and all you have said about replacing the coil was the probable solution. Code was cleared but within a few miles it was back on again.

I'm now awaiting a cost of a replacement coil and it has been suggested that all 3 (?) should be replaced.

The car is on a 56 plate with 65000 on the clock.

[ColinBarber]

No I don't agree that 3 should be replaced and why even stop at 3, why not all 6? They don't all fail at once and one failure doesn't affect others. These aren't VW/Audi coil packs that all fail together just outside the warranty period ;)

Worth just reseating/cleaning the connector first.

[Seafarer]

Hi all - had the same fault recently 0355 which was intermittent - had my local garage do a diagnostic check and he recommended swapping the coil and spark plug into different slots to confirm a coil malfunction. Swapped coil from 5 to 4 and spark plug 5 to 2.

Fault duly returned and code 0354 came up which confirmed the problem coil. Spark plug ok and as they were changed in June I would not have expected a problem.

New coil fitted £125 plus VAT.

Went on line looking for coil 90919-02251, as stamped on the old coil, and found prices from £8.95 ( China ) to £137 plus vat in UK.

Seems that there are cheaper alternatives which match up so I shall investigate further. Having watched the mechanics replace the coil I know I could do the job on pots 2 -4 -6 myself but 1 3 and 5 means removing hoses etc to get at them and then, would I have the tools ?

Great car though and a little treat in my old age !!

[Seafarer]

Now I know " how " to get at the coils I shall do the clean up recommended by fellow members before I spend £125 again !!!

Thanks for posting the advice - it certainly helps and gives comfort when a problem occurs.