Strange! Cooling fan causing coil pack malfunction? PP2000

[Zash]

Hi Fellas,

206 CC 2.0 (206 2.0 GTI)

Peugeot Planet 2000 screenshot [attached].

Diagbox shows code P0350 (Coil pack etc)

A short while after I start the car, the cooling fan comes on as usual, but when it does, the engine seems to almost die and sometimes does die. The fan goes off after ~5 seconds. Rinse and repeat after every 30 seconds or so. Every cycle, it throws up 5 errors as shown in PP2000 screenshot above. Diagbox code above too.

What I think is happening is that there is a short circuit in the ECU fan sensor circuit. This short is triggered when the fan comes on. I believe the short drains the battery/alternator for a fraction of a second, therefor not allowing enough current to ignite the spark plugs in that instant, hence the P0350 fault. I believe the P0350 Coil faults are a red herring.

I think if I ix the fan issue, everything will be OK.

What do you guys think? How best to fix the fan issue?

Kind regards,
-- Zash

[IanL]

That is very likely to be the cause. The problem may be the fan, or more likely, the relay which controls it.

The fan relays are mounted to the side of the fan. The upper is the low speed relay, the lower is the high speed. They are identical 35 Amp relays, so you could first try swapping them. If the problem only recurs when the engine is really hot (high speed relay operates), you would know which relay to replace.

Let us know how you get on.