View Full Version : P1300 Code Repair (ECM)

06-16-2016, 06:58 PM
My 97 Celica GT convertible started running rough and then not running at all. Dash cel was P1300 code=return signal (igf) to computer (ecm) problem. I started replacing the easy things that troubleshooting requires: coil, igniter, check continuity between igniter and ecm - same problem. Removed the ecm and replaced the electrolytic capacitors - a total of five. Reinstalled the ecm and it runs perfectly with no codes. Please note - this application requires special capacitors - low esr, high temp, high ripple rejection. I removed my old caps and checked them with a capacitance tester, it showed they were all within common specs but, esr, ripple, etc can't easily be tested - by this redneck anyhow. I've attached a link to an excellent article by a gentleman in the Lexus community. Toyota and Lexus products share these same ecm/ecu potential problems. Cowboy's article has great info and even best places to buy the caps. I ordered mine from Mouser. I talked to Cowboy on the phone and he had a good point - if you buy a replacement ecm from ebay, craigslist, etc., it will have old caps that deteriorate with age so, they probably need to be replaced, to be safe. Cowboy is on facebook as lscowboyls, I believe. He is in the Birmingham area (Vestavia), works on these computers and has a phone no. listed on his fb page.

I hope my experience will help someone with this common problem. LEGAL NOTE - I can't be responsible for any damage, mistakes, bumblefootedness, divorces, etc. Be your own judge and be careful. This does require some skill.

Y'all have a good day and God bless.


06-17-2016, 01:08 PM
Thanks for posting the info up. The ECU capacitors seem to be a common issue across a lot of Toyota ECUs.

Great info.