91 Galant GSX automatic transmission stuck in limp mode (stuck in 3rd) FIXED!

[Tommyboy62]

Unheard of follow up: Thank you everyone who posted here with the limp mode electrical problem. My 91 Galant GSX automatic transmission limp mode (only park, nuetral, reverse & 3rd gear) problem is fixed. It was the centralized capacitor on the transmission computer (ECU aka ECM) board leaking (tiny trickle indicated by dullness/lack of shine like a tiny stream leading from capacitor) as it got hot & drying up when it got cold (causing intermittent failure) & the fluid eating into the board causing shorts. Mine was undiagnosed so long it eventually caused the corner chip to fry (now causeing permanent limp mode) that was very difficult to notice (use a magnifying glass - mine looked like a pencil eraser stabbed it as it was round) & even a repair place couldn't fix it - probably can't buy the chip. $160 including shipping to repair (I tried, AvPro Company, PO Box 6612 Ft. Myers Beach, FL 33932 Phone: (239) 849-0981 (Nick) Email: [email protected] or search for another, but this place was helpful) if yours is only the capacitor. I had to buy a new transmission computer from the dealer (dealer only/manufacturer) for $797.44 (prepay) total including tax here in CT. The ECU aka ECM (part # MD750676 on my 91' GSX) is a brass colored box 6.25" x 6.75" x 1.5" located inside the car behind the stereo/radio bolted to the floor of drive shaft hump with one bolt & to the firewall with 2 bolts. If yours is discovered before any further damage is done due to this leaking capacitor simply replace this 99 cent capacitor with a 50V, 47micro farad, high temperature resistance, larger one as this is what was goofed up on at manufacture. Also clean the capacitor fluid off to prevent further damage. There are instructions & even pics here on this forum or links. This was a follow up to help others with what was a nightmare for me for the 2 years I had no car at all as 5 repair places couldn't fix my car! Anderson Elec in Waterbury, CT said it was the transmission, City Automatic Transmission in Waterbury, CT rebuilt ($1390) my transmission 12 times durring the intermittentcy with about 1 month waiting each time it went back, King Transmission in Torrington, CT wouldn't touch, Marks Precision Electrical in Prospect, CT tried twice ($ replacing engine computer etc $), the Mitsubishi Dealer in Torrington, CT (perminently out to lunch anyway) wouldn't touch it! Thank you all & you are welcome... "pass it on"...

Tommyboy says "Pass it on"