[2001 V70 2.4T] Ignition coil cylinder 3 and cylinder 5, signal too low (P1354,P1358/ECM-3320,ECM-3340)

Post by **prwood** » 29 May 2019, 07:47

Within the past couple of weeks, I have noticed some rough engine operation, the check engine light is lit, and an OBD scanner pulled up codes P1354 and P1358. VIDA shows codes ECM-3320 and ECM-3340, which correspond with the OBD codes and indicate low signal in ignition coils 3 and 5. VIDA also shows ECM-3503 and ECM-3533, which indicate misfire in cylinder 3.

VIDA had the following freeze frame data stored:

: ECM-3320 Freeze Frame Data; ECM-3320-freezeframe.png (48.08 KiB) Viewed 7476 times

: ECM-3503 Freeze Frame Data; ECM-3503-freezeframe.png (47.82 KiB) Viewed 7476 times

My most recent maintenance before this began was replacing all five spark plugs, but it did not start immediately after replacing the spark plugs. Since then, I have done the following to troubleshoot:

- Disconnected and inspected all 5 ignition coils, spark plugs, and ignition coil wires
- Disconnected and inspected two ground wires adjacent to ignition coils
- Cleaned all electrical contact surfaces with QD electric cleaner spray
- Wrapped with electrical tape a few spots where bare copper was showing on ignition coil wires
- Ran fault trace procedure for ECM-3320/ECM-3340:

: ECM-3320 fault trace; ECM-3320-faulttrace.png (83.56 KiB) Viewed 7476 times

This showed 0 resistance for both ignition coil connectors in question.

Any suggestions on where to look next? I could try swapping around the spark plugs to see if the problem moves with them.

Post by **abscate** » 29 May 2019, 08:00

How old are the coils?

Remember - if its your car, put one new one in the trunk, then write an epic tale of pulling across 8 lanes of Route 128 at 1700 hours and then parking in the break-down lane (which is an open lane in MA during rush hour) and replacing it before you get hit by the Garbage truck

If its her car, five new coils.

When you pulled ECU to check the continuity, did all the connections look fresh with no corrosion?

Post by **prwood** » 29 May 2019, 08:14

abscate wrote: ↑29 May 2019, 08:00 How old are the coils?

Coil #4 is relatively new... in fact I think it's the one you sent me a while ago.

Coils #1,2,3,5 status unknown. I could swap coil #4 into #3 and #5 for testing purposes.

abscate wrote: ↑29 May 2019, 08:00 When you pulled ECU to check the continuity, did all the connections look fresh with no corrosion?

Yes, everything looked pristine, in fact. I gave both the male and female sides of the interface a shot with QD electric cleaner and dried with compressed air just for good measure, though.

Here's a recent photo of the ignition coils... BTW for those keeping score, I did in fact redo the wire looms recently (when I was replacing the spark plugs).

Post by **abscate** » 29 May 2019, 08:50

errr.. those are pretty old. That Number 1 is 19 years old.

I think it might be time.

Definitely move them, one at a time, and see if problem moves.

Post by **prwood** » 29 May 2019, 08:53

abscate wrote: ↑29 May 2019, 08:50 errr.. those are pretty old. That Number 1 is 19 years old.

I think it might be time.

Definitely move them, one at a time, and see if problem moves.

Whoah, how can you tell? I can barely make out any of the markings?

Post by **abscate** » 29 May 2019, 11:17

prwood wrote: ↑29 May 2019, 08:53
abscate wrote: ↑29 May 2019, 08:50 errr.. those are pretty old. That Number 1 is 19 years old.

I think it might be time.

Definitely move them, one at a time, and see if problem moves.
Whoah, how can you tell? I can barely make out any of the markings?

"You have to know these things, to be a King Moderator"

00W44 date code on Coil one Year 2000 Week 44

Post by **prwood** » 29 May 2019, 13:25

So my current plan is as follows:

1. Swap suspect coil 3 with known working coil 4
2. Swap suspect coil 5 with known working coil 2
3. Drive and see if error codes move with coils, stay with cylinders, or go away entirely
4. Replace failed coils with $15 coils pulled from junkyard
5. If junkyard coils immediately fail, replace with $47 new Bosch coils

Post by **DeadEric** » 30 May 2019, 05:23

Check inside the boot of the coil. I've had the metal piece on the end of the spring fall off unnoticed. With that missing, the spark has to jump twice and will give those codes.

Boot and spring sets are cheap, I recommend them when doing plugs.

Post by **abscate** » 30 May 2019, 05:46

Peter..I’ve got a Brand new one or two and several Boston Trips scheduled

Post by **prwood** » 30 May 2019, 07:18

TL;DR: I swapped ignition coils/boots/springs last night and the trouble codes came back to the same cylinders, so it seems that the coils are not the issue.

1. Swap suspect coil 3 with known working coil 4
2. Swap suspect coil 5 with known working coil 2

In both cases, I swapped the coil, boot, and spring as one unit. No change to spark plugs. After erasing all DTCs, and going for a brief test drive, the same codes came back:

ECM-3320 (P1354) - ignition coil 3 signal too low
ECM-3340 (P1358) - ignition coil 5 signal too low

Here are the freeze frames from the latest instance:

ECM-3320:

: Screen Shot 2019-05-30 at 9.08.50 AM.png (48.1 KiB) Viewed 7402 times

ECM-3340:

: Screen Shot 2019-05-30 at 9.09.07 AM.png (48.1 KiB) Viewed 7402 times

Given that the codes indicate failure on the same ignition coil even after swapping said ignition coils, it seems logical that the fault is not in the coils but in the wiring leading to the coils. Since I tested 0 resistance between the ECM terminals and the ignition coil connectors, is it possible that there is still a fault in the wiring, but one that occurs under conditions that the ohmmeter cannot duplicate?