I recently had a CEL come on and was told the code was a P1486, cooling system malfunction. The coolant was low so I topped it off and cleared the code by removing the battery cable but code has reappeared three times. Dealer wants $900 to replace ECU but I think its odd that the code started because of low coolant in the first place. Any ideas that keep me from buying an ECU would be greatly appreciated.

 

New ECU???? NNNNNOOOOOOO!

The only way the ECU knows anything about the cooling system is from the temperature sensor in the end of the head below the distributor. Look for dirty/loose/corroded connections.

 

make sure that radiator is full, system bled properly,no leaks, cap is ok, , than i would replace the thermostat.. I had a Nissan with the same issue ( cooling system malfunction ) once and a new t-stat fixed it , code never came back on again ,, it has been almost 1 year so far ..
give it a shot, t-stat+ coolant will cost you around 30-40 dollars if you do the work ,

 

No luck with thermostat, cap, etc or any obvious connector problems.What manual would you recommend that will help me troubleshoot engine electrical such as the temp sensors? Where is the best place to buy it?

 

www dot helminc dot com

Best shop manuals are from Helm - that's the factory book. Pricey at about $80 but VERY detailed.

 

Yea, that dealer is trying to scam you. I wish I could help more, but sometimes you just can't diagnose on line; just give some suggestions. I have a 95. I have "heard" about how the computer has to re-learn, with a number of (key) starts. Not sure about that, let us know.

 

do the fans ( both ) work properly??
they both come on with a/c on and both come on when engine is warmed up ??

 

Both fans cycle together with A/C and with engine heat. I did find a Honda service bulletin about 2000 Accords with ECU problems that concerned me though. Removed my ECU and got the part # off it (P/N 37820-PAA-A52) and sure enough it was on the list in the bulletin that Honda would have replaced if the car still had warranty. Makes me wonder if the dealer is right? Check out the link below for the bulletin from Honda.

driveaccord.net/forums/attachment.php?attachmentid=6100&d=1160062042"][U][COLOR=#0000ff]www.driveaccord.net/forums/attachment.php?attachmentid=6100&d=1160062042

 

That repair is going to be expensive at a dealership, because a new PCM from the dealer is $$$$.

You may be able to pick one up at a junkyard for much less money. Get a PCM with the 37820-PAA-405 part number.

You would also have to reprogram your keys, because there is an immobilizer on your car. I know there is a way that you can reprogram the keys. That info may be in your owner's manual. If not, I know that has been posted on here.

 

All I've seen (& posted myself) is the procedure for the remote-lock transmitters. Programming the immobilizer is a completely different thing. I think it might need the Honda scan-tool.