1999 V70 P0351 - P0355 Ignition Coil Primary/Secondary Circuit

[V701987]

Hi everyone,

My 1999 V70 has been giving the following codes:

P0351 - Ignition Coil "A" Primary / Secondary Circuit
P0352 - Ignition Coil "B" Primary / Secondary Circuit
P0353 - Ignition Coil "C" Primary / Secondary Circuit
P0354 - Ignition Coil "D" Primary / Secondary Circuit
P0355 - Ignition Coil "E" Primary / Secondary Circuit

as well as:

P0328 - Knock Sensor 1 Circuit High Bank or Single Sensor.

A few months before I got these codes I had just a "P0351 - Ignition Coil "A" Primary / Secondary Circuit." Thinking it was a bad ignition coil, I replaced it. Now it is showing a problem with all the ignition coils.

Other than these codes, I have not had any issues with how the car drives - starts and drives fine, not stalling, etc. It's been about 6 months since I got the codes. I have cleared them multiple times but they always come back after a few miles of driving. Since I haven't noticed any issues with drivability, I have let it be, but now I'm thinking I should get on top of it before something fails.

I'm thinking that there may be a problem with the ignition coil wiring harness. Could that be the cause of this? What else could be causing this? Is it an easy job replacing the harness?

Thank you in advance!

[abscate]

The coils all get a common 12V from the main relay, so fault trace the voltage from coil back to the battery.

Coil voltage should be very close to battery voltage, like within 0.1V or better