Hello! I'm new to the Volvo world and im having a hard time diaging this S40.

Fault codes : 6110 Engine Cooling Fan(FC)
3503 Misfire at least one cylinder
3355 Misfire on Cylinder #3

I bought this car for $1,000.00 and drove it home shaking, everything works but the following:

1. Fan and module work, Not getting PWM signal from ECM.
2. Replaced all coils with Bosch, has new NGK Iradium plugs (i did not change them the dealer did)

Misfire under load or when cold on #3 only. If you rev the **** out of it then drive it it works fine then the miss come back after driving.

Have a snap on scanner and everything looks good except the cams are not changing. Any ideas where to look next?

Thanks,

Gerry

 

Try swapping the #3 coil pack with one of the others and see if the misfire follows the coil pack.

 

Found # 7 & 8 pins on ECM bent. re pinned ECM fixed the fan issue. Changed spark plugs to OEM Volvo R6 plugs no more miss.

Thanks!