check engine light

[vect0r]

my light came on in my 97 neon, and I got these error codes:

12 Direct battery input to PCM was disconnected within the last 50 key-on cycles

35 Rad Fan control relay circuit


anyone know how I can fix those problems?

[carson blocks]

Originally posted by vect0r
my light came on in my 97 neon, and I got these error codes:

12 Direct battery input to PCM was disconnected within the last 50 key-on cycles

35 Rad Fan control relay circuit


anyone know how I can fix those problems?


The #12 error could be caused by a number of conditions.
You may have disconnected the battery recently. The battery may have been run completely dead recently. You may have disconnected the PCM recently, or you may have a wiring problem which caused the constant +12v power to the PCM to be disrupted. This code should clear itself within 50 key-on cycles.

To troubleshoot the #35 error, Check to see if your fan comes on when the car is up to temp. Check the coolant temperature sensor and the wires coming from it to ensure they are properly connected and undamaged. Check to see if you have any burned fuses.

I'm not much of an auto-repair expert or anything, but hopefully this gets you started tracking your problem down. Good luck!

[vect0r]

thanks, the fan DOESN'T spin when it gets really hot.. could that be a relay?

I'm going to check the fuses in a bit

[camero]

Your PCM (ECU) controls the fan so that could be your problem. Its malfunction is causing other problems. Try resetting it maybe?

[carson blocks]

Originally posted by camero
Your PCM (ECU) controls the fan so that could be your problem. Its malfunction is causing other problems. Try resetting it maybe?


I Wouldn't just reset the ECU before checking a few other things out first. When you reset the ECU it has to relearn some operating parameters which could lead to poor driveability during the relearning period. I'd check the fuse and wiring first.

If you can get the schematics from the manual it may aid you in tracking this down. Or if you can find a junkyard relay for cheap enough, you can try replacing it.

[vect0r]

So resetting it would cause the car to run shitty? For how long?

And how would I go about resetting it?

[canadiandaytona]

Unplug Battery for a few minutes

[h22aseller]

unplugging it won't make the car run shitty, it'll just need to idle for about 5-10 minutes to reset itself and the fuel economy won't be as good for about the first 100km. it won't be misfiring or anything like that.