Code 51

[8T4Gold]

;help So we took the '84 for a spin today.(our first time out with this car). During our time away from home, the check engine light came on. I hastily checked all temps and pressures, all were OK. We put on about 300 miles, and when we got home, pulled up code 51. What does this mean, and how do we fix it? The car seemed to run fairly well.

 

[geekinavette]

Code 51 is pretty serious...it means the EPROM in the ECM is either failing or has failed, and it may be running in "limp home" mode.

Try disconnecting the battery...pull the ECM down, remove and re-install the EPROM...it could be just a flaky connection on one of the EPROM pins. Put it all back together and see if the code 51 comes back.

If it does...whatever you do...do NOT go spending hundreds of dollars on a replacement EPROM! Shoot me a PM and I can send you a stock replacement EPROM.

Bill