94 Camry V6
I drove to work without any issues. 10 hours later when i tried to start my car, there was 0 power from the battery. I found the ground on the battery very loose. I wiggled it, my car started and i drove home without any trouble EXCEPT I was getting code P1600. I fixed the battery problem but the code wont reset with the code reader. Will this go away after a few cycles?

 

This code for backup power to ECM.

Try disconnecting battery cables. Then touch battery cable ends together.

 

Touching the cable ends together didnt help. Thank you for the suggestion. I drove it a while and the emissions markers reset but the check engine light/P1600 code was still on. When i turn off the car, the emissions markers didnt save. Any more ideas?

 

Check for 12v at the ECM electrical plug wire.

Remove glove box to access ECM behind it.

Look for a White/Blue wire on the outside plug nearest passenger side. Check for 12v.

Power comes from EFI fuse which routes direct to battery. The wire should be hot at all times.

There is another wire of same color wire for one of the injectors.

If no power, check wiring.

If power replace computer. Check Ebay, internet or auto salvage yards for replacements. Replace only with one of the exact same part number.

 

Ok sounds like a simple process. Will it hurt anything if i continue to drive it until i have more time next weekend? Thank you for your help.

 

No damage, OK to drive.

If you need a photo of ECM to identify part, search Ebay. Lots of ECM's for sale with photo.

 

I finally took the glove box apart and found that there is "always on" power to the ECU. So im looking at e-bay for a possible replacement. Is the only important part number the one in white letters/black background (89661-33350)? There is also a set of black numbers /white background (175000-5785 12V). Sometimes i see an ECU with the the white numbers matching, but the black p/n is 1 digit off. 175000-5785 vs 175000-5784. Does this matter? Thanks

 

89661-33350 is the correct number. Get a computer with this number.

See link below:
89661-33350 - Genuine Toyota COMPUTER, ENGINE CONTROL

 

Pulled the old ecm out and found some kind of fluid (i think power steering) inside the plug in's. Replaced it with an ecm from the junk yard, temporary sealed it in plastic until i can find the leak. Works great again! Thank you.

 

Great job!

Good idea about the plastic.

You can also apply dielectric grease to the electrical plug connections to keep out fluid.

Smell the PS fluid in the PS reservoir and compare. Also compare to engine coolant which may be also pink.