ephone

OK. Thanks. I will try to replace the spark plug today. Can I do it by myself?

BTW, when I look at my original (replaced) ignition coil, it did have some stain there. The color is just like the color of steel after oxidation.

ephone

If it is the faulty wiring goes into the coil, what can I do then?

ephone

BTW, what will be behind the logic for the following events:
(1) three lights on (check engine, vsc, trac off)
(2) replace the ignition coil, all lights off
(3) after about a week to 10 days, the three lights come back on

If it is the wiring problem, will (2) still happen? Thx.

lexusfan05

Did you check the battery connector to make sure the coil and other ECUs getting full voltage? Once I lived months with flaky power sliding door on a sienna, only to find out a bad battery connector was the culprit.

ephone

I did some work this afternoon and get the three lights (check engine, VSC, TRAC OFF) off.

I am not sure whether I fix the problem. However, here is what I did:

I mentioned before that I notice there is some discolor on my replace No. 6 ignition coil with some brownish steel oxidation stuff. I thought that is a bad ignition coil since the error code P0356 pointed to that one. So I replaced it with a BWD brand one from pepboys.

Well, today I take No. 4 out and notice it also looks almost the same as the No. 6. I use paper to wipe them clean. So what I do next is to take out the new BWD one out. I put the No. 4 into No. 6, I put my original No. 6 into No. 4. Basically, I exchange the places for the two original ignition coils as people have suggested here. Well, the OBD-ii code still indicated the P0356. I am not surprised that since auto zone people told me that even it was fixed, it will take time for the error to go off.

Next, I did what I have not done before. I disconnect the battery for about 20 minutes and then reconnect. So the system restarted and initialized again. Surprisingly, all the three lights were off and the car is not shaky anymore when I started it.

I still do not know what is going on and what was the problem initially. I still have no idea whether it is fixed. I have my finger crossed. But I know I need return the BWD ignition coil back to pepboys since it seems that the ignition coil is not the problem.

lexusfan05

This makes me more suspicious about the battery, that you are making a temporary good connection when you are reconnecting the battery. When you take the coil back to store, have them check the battery and the terminal connections.

ephone

My question is that how battery connection will give out a P0356 code. I am quite puzzled here.

alchemist

iTrader: (1)

Clean the battery terminals and check the battery and alternator at autozone.

ephone

The lights come back again.

Can you tell me a little more about the logic behind it? There are many things that I can do. However, I am not sure what is related to the P0356 code?

alchemist

iTrader: (1)

These cars become real finicky with battery issues. Its a simple check and something to rule out once complete.

lexusfan05

ECUs can act up when the power supply is not solid. There is no way to tell whether the P0356 code is real, or the ECU is acting up. The VSC and other non-related lights are even more indication that the ECU is not happy - but it's a guess.

ephone

Thanks. I will ask autozone to check my battery later today. BTW, where is the alternator? How do I tell the auto zone people to check that? Thx.

lexusfan05

Autozone guys will know how to check alternator. It's next to the engine, driven by the engine through one of the belts.

alchemist

iTrader: (1)

You check it with a multimeter to the battery while the engine is running. You don't necessarily need to access it.

ephone

Now the error code is P0354.

It seems indeed the ignition coil on No. 6 has problems since I exchanged No. 4 and No. 6 last time.

I will try another ignition coil from auto zone and see whether this time it will be ok. Thx.