SM/check engine light on/brake light question

Highspeedlowdrag

New Member
Joined
May 27, 2018
Hey guys. Good morning everyone. Alright ive been pretty good about figuring out these problems but this one is kinda weird for me.

Drove the car for a few miles, turned it off (it rained for a little bit) turned it on about an hour and check engine light came on. Drove it home, noticed the scanmaster was off and a/c wasnt working. I started to diagnose the ECM being murdered by the fan relay. Soooo im going to say the ECM is dead at this point.

Sure enough i have a ton of corrosion and 1987 tar grease stuff on it. I clean the delay relay up and ran out of time. Woke up this morning and plugged it in just to see if it magically worked.

Well the gremlin moved apparently. I turned it on, and the check engine light is off, a/c works and car run. BUUUUT the brake light is on now and i have no brakes. (Still the original factory brake setup) the brake pump does not work with light on the dash.

Please any help lol. I dont want to replace the ECM if i dont need to. Any ideas?
 
Disregard. Cleaned all the relays very well, checked, power yo all the relays, they were all good. Not sure what the problem was with that. The brake light being on and pump not working... checked the “relay fuse” and found a blown fuse. Replaced the fuse and all is great. The fuse was not blown in the initial part of the diagnosis. Most have blown it when i took all the wires off and cleaned them. Maybe they touched.
 
All the ECM wants to know is when you hit the brakes. I'd say it's ok. You have a powermaster problem.
NOTE: remove battery negative when fooling around with wires.
 
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