I replaced my engine wire harness last weekend to diagnose a non-start/severe misfiring problem my car had developed. Although the car starts now, it is still misfiring on cylinders 2 and 5.

I am getting this error code:

22 Ignition output 1 or ignition coil for cylinder 2 and 5 (Engine 111, cylinder 1 and 4)

A brand new set of F8DC4 spark plugs has been installed in all cylinders. I have also tried moving the suspected dead coil pack from cylinder 2 to cylinders 6 and 4 as well as moving the suspected spark plug wire on cylinder 5 to cylinders 1 and 3. The misfire still stays with cylinders 2 and 5.

With the ignition on, I am seeing 12V on the signal wire running into cylinder 2 coil pack which is the same as the other cylinders. I'm not sure what else to check or look for at this point. Any help would be great, thanks.

Did you move the boot connector from the bottom of coil also ? or just moved coil pack?

I moved the entire coil pack with the boot attached. I didn't remove the boot connector underneath the coil pack by itself. Should I?

What method are you determining cylinder 2/5 is misfiring?

I have tried using both an inline spark tester and an inductive timing light on cylinder 5 spark plug wire to confirm that it is not firing. I cannot test cylinder 2 with the inline spark tester tool due to the spring loaded connector at the bottom of the boot.

Disconnecting the signal wire from the coil pack on cylinder 2 doesn't change the idle at all. It is still very rough and runs as if it is about to die. Also checking the condition of the spark plug #2 tip shows evidence that it has never been fired since installed last week.

I just tried swapping the boot underneath the coil pack around with the other two and still doesn't make a difference.

if that boot is bad it will take out the other cylinder as well,ie if 2 is bad 5 wont work , sounds like boot is bad, unless you move it to another cylinder which I don't think you can because wire is different length, but I think you can move boot to another set of cylinders 3-4,1,6?by unscrewing boot? right? if problem moves there you go bad boot

I was able to move the boot underneath the coil pack for cylinder 2 to cylinders 4 and 6. 4 and 6 fired fine and 2 was still not firing, so I am ruling out a bad boot at the moment.

The only thing I can think of at this point is a faulty ECU since the wires were completely shorting out with the original wire harness, maybe some electronics were fried?

I'm not sure how to test the signal wire for the coil pack, only checked the voltage with key on engine off seeing 12V.

I was searching the forum some more and it sounds like this guy has a similar problem as mine: m104 Misfire

Conclusion from that thread was a bad ECU. I'll have to try a new ECU and see if the problem is fixed.

Sounds like a bad ecu ,if you tested wiring from coil to ecu ,and wiring good ,looks like ecu,you can find these ecu at pickyourpart

Test pins from coil negative to pins 9,10,21 of HFM ecu,the coils have shared voltage,triggered by ecu (HFM)on negative side of coils,what city are you in?

I switched the ECU out with another spare unit, all cylinders are firing now. Problem solved.

The ECU is likely reparable, in any ignition module the power transistors usually fail first. ( The " ignition module " is integrated into the ECU )

There are 2 coil boot failure modes.

One is where the resistor loses conductivity.. It may arc across for a while but eventually it will open. When it opens it will take out 2 cylinders and eventually the coil.

The other is where the boot punctures and the electrical energy never makes its way to the spark plug. In this case it will take out the cylinder attached to the boot but not the one what uses a plug wire. ( 2 and 5 for example )

All of this applies to the plug wire as well.

He got a code because apparently the ECU monitors ignition coil current or the inductive kick when a plug fires.

Another wrinkle. On my 97 C280 and SL320, if there is a specific cylinder miss fire for say 15 seconds, it will shut off the injector to that cylinder to prevent cat converter damage. This can cloud diagnosis when dealing with an intermittent ignition miss fire.

I've got this same problem. Anyone have a good ecu i can try ? Pins 9, 10,21 are the ignition coil wires on the ecu? I have an 1994 E320 wagon.

Thanks

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1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius