BenEvans 0 Report post Posted February 17, 2011 Hey all, I needed to replace the automatic transmission in my 1991 525i with the m50 and ZF 5hp-18 transmission. my mechanic had a spare mint one but it was from an e36. now as far as we could see they are identical 5hp-18's except that the e36 'box used a slightly different plug to go to the ECU, however they are still both 15 pin plugs. i went searching around and was told by a few people that you could just cut the existing plug off and solder on the correct plug on (from the e36) as the wires were the same. i have since put the new trans in and soldered the new plug on, trying to match the wires colour for colour. this however has not worked and the ecu still picks up a trans fault and it is stuck in 'limp mode'. Has anyone done this conversion or does anyone know anything about it... im rather stuck. Thanks heaps Ben Quote Share this post Link to post Share on other sites
