PCM (Computer) melting down ignition coils

[aaronsb]

Hey everyone,

I have a 2007 cx9 that melts down the #6 ignition coil. The dealer I'm bringing it to is sort of driving me nuts by trying to blame it on spark plugs and aftermarket parts. Mazda USA is replacing the PCM under the powertrain warranty, however.

Have any of you heard of this happening? Basically, the signal wire from the PCM is pulled to ground all the time, causing the coil to continuously fire, turning it into a large resistive heating element instead of a spark coil.

Oh yeah, it's going to take at least two weeks to order a new PCM, because they're on backorder.

Aaron

 

[table5511]

Bulletin 01-026/11

Taken directly from the tsb:

"ENGINE ROUGH IDLE AND MIL ON WITH DTC P0351, P0352, P0353, P0354, P0355, P0356

Some vehicles may experience a rough idle and MIL illumination with one or more of DTCS P0351, P0352, P0353, P0354, P0355, P0356 stored in the Powertrain Control Module (PCM) memory. In some cases, ignition coil (IC) damage may be found.

This repair will be covered under Mazda's Emission Warranty (96 month / 80,000 miles)."

 

[Canadianx9]

On my way to work the power cuts out and the engine is running very rough. Engine light blinking. Checked the codes when I got home. I got p0351, p0352, p0354. So I am thinking great I have 3 damaged coils. Being a 2007 it is out of warranty. It has 59000 kms. Had it towed to a Mazda dealer who then said it was the number 2 coil. The coil was replaced and the spark plug too. However after I got it back the cx9 was still running rough. But it wasn't throwing any codes. Took it back immediately and then they said it was the PCM. Luckily that is still under warranty. Now I have a skyactiv for a loaner.

 

[table5511]

Look on the bright side, at least your dealer gives you a loaner. (mine does not)

 

[Lindyrect]

Look on the bright side, at least your dealer gives you a loaner. (mine does not)

At least mine used to drive me over to Enterprise.

 

[ceric]

The dealer I goes to (Oak Tree Mazda) always give me a Mazda3 loaner for warranty issues.
I only pay for the gas (< 1 gallon usually).
This has happened 2-3 times during my 4 years of ownership.

 

[judy_moan]

I just had the powertrain control module replaced on mine - on the way to church the engine was misfiring, when home, towed the next day. Dothan Mazda said it was a coil, which were back ordered. Replaced a coil, but didn't fix the problem, two other coils were split and replaced but still ran rough. Upon contacting the manufacture they found out it was the PCM. It only took them 29 DAYS to figure it out/get parts and fix the problem. If you are in the SE Alabama area I would not recommend them as a dealer to go to. Of course, my car just hit 100,000 miles so it's past the 80,000 mile warranty.

 

[table5511]

Welcome to the forum, Judy

 

[ceric]

I just had the powertrain control module replaced on mine - on the way to church the engine was misfiring, when home, towed the next day. Dothan Mazda said it was a coil, which were back ordered. Replaced a coil, but didn't fix the problem, two other coils were split and replaced but still ran rough. Upon contacting the manufacture they found out it was the PCM. It only took them 29 DAYS to figure it out/get parts and fix the problem. If you are in the SE Alabama area I would not recommend them as a dealer to go to. Of course, my car just hit 100,000 miles so it's past the 80,000 mile warranty.

Did you try to get your money back? The money you paid for the coil replacement.
Obviously, if the PCM was the problem, replacing the coils might not be needed at all. You shouldn't have to pay for that.
If this was under warranty, no one care.

 

[veyl_oiuja]

hello guys! I don't know if this is the same thing that happen to me but when I got fuel from a random gasoline station from half moon bay and went to downtown sfo, when I tried to start the car it started to misfire and cel was blinking and remained on. and then after a few miles driving it, it went okay and I just had to erase the code. I forgot the code number but it was a misfire and then a few weeks later on it did it again and but the cel blinked and went off, and the code was for an open cylinder 1, I believe. Is there something to do with the pcm and is it easy to replace? thanks!

 

[table5511]

veyl_oiuja .... in your case I'd be willing to bet its an ignition coil(s). They dry out, form micro cracks, and when moisture gets in the cracks they start misfiring. You can J.B. Weld the entire plastic surface of each coil, or start replacing them.

 

[veyl_oiuja]

veyl_oiuja .... in your case I'd be willing to bet its an ignition coil(s). They dry out, form micro cracks, and when moisture gets in the cracks they start misfiring. You can J.B. Weld the entire plastic surface of each coil, or start replacing them.

We did a tune up on it. Replaced the spark plugs. So far so good! Even hit 110mph easily! Hehe! Before I was having a hard time even going to 100. So I guess the spark plug was no good and they are damn motorcraft plugs!

 

[CX92ENVY]

I had the same issue. I had a coil pack thet pretty much melted and cracked. It also fried the PCM! Sent the PCM to Circuitboardmedics.com and replaced the coil pack and worked great. Do not replace the coil pack and run it with repairing the PCM or it will cause the new coil pack to fail. The PCM tells it to fire constantly and melt!

The guys at Circuitboardmedics.com were great even when it failed the second time in 2 months!!!

 

[LUCKYALMOM]

Where can I find the complete Bulletin 01-026/11?

Bulletin 01-026/11

Taken directly from the tsb:

"ENGINE ROUGH IDLE AND MIL ON WITH DTC P0351, P0352, P0353, P0354, P0355, P0356

Some vehicles may experience a rough idle and MIL illumination with one or more of DTCS P0351, P0352, P0353, P0354, P0355, P0356 stored in the Powertrain Control Module (PCM) memory. In some cases, ignition coil (IC) damage may be found.

This repair will be covered under Mazda's Emission Warranty (96 month / 80,000 miles)."

 

[table5511]

Luckyalmom, welcome to the Mazdas247 forum!

Send me a private message with your email address and I will send you the full bulletin on this subject.