my car only runs when the "D" connector is unplugged from the ECM
Thread Starter
Joined: Jul 2008
Posts: 4
Likes: 0
From: san bernardino, ca, us
my car only runs when the "D" connector is unplugged from the ECM
i have a 93 prelude si that all of a sudden died on me on my way to work. i have been throwing parts at this thing and nothing seemed to work. so far here is a breakdown of what i tested and did to the car.
i replaced the main relay with one from a junk yard
replaced the fuel pump
replaced the coil
replaced the distributor
checked all fuses
checked to see if i had voltage at the MAP... nothing
checked to see if i had volatge at the TSP... nothing
frustrated that the fuel pump would not run for two seconds and the car would not fire i came across this post.
honda civic ecm test
http://www.askmehelpdesk.com/c...19451
the guide said to check voltage at the MAP then unplug the D connector from the ECM and test for voltage there. upon keying the car over to test for voltage at the ecm my fuel pump ran for two seconds and the check engine light stayed on. i tested the pins on the ECM and found they had 5V.
i then keyed the car over and it stays running. but really rough.
as soon as i plug the D connector back into the ECM and try to start the car again it shuts down.
do you think my ecm is toast?
when the D connector is plugged into the ecm the fuel pump wont run and i have no spark. since the car runs with it disconnected i can rule out that my main relay it working and my ecm ground at the thermo housing is good.
would it be possible to swap in an accord ecu form a non vtech ODB1 model? i see all kindas of early 90s accords in my local yards. i know where a really nice almost complete F22a car is. can i steal that ecm and test it?
i replaced the main relay with one from a junk yard
replaced the fuel pump
replaced the coil
replaced the distributor
checked all fuses
checked to see if i had voltage at the MAP... nothing
checked to see if i had volatge at the TSP... nothing
frustrated that the fuel pump would not run for two seconds and the car would not fire i came across this post.
honda civic ecm test
http://www.askmehelpdesk.com/c...19451
the guide said to check voltage at the MAP then unplug the D connector from the ECM and test for voltage there. upon keying the car over to test for voltage at the ecm my fuel pump ran for two seconds and the check engine light stayed on. i tested the pins on the ECM and found they had 5V.
i then keyed the car over and it stays running. but really rough.
as soon as i plug the D connector back into the ECM and try to start the car again it shuts down.
do you think my ecm is toast?
when the D connector is plugged into the ecm the fuel pump wont run and i have no spark. since the car runs with it disconnected i can rule out that my main relay it working and my ecm ground at the thermo housing is good.
would it be possible to swap in an accord ecu form a non vtech ODB1 model? i see all kindas of early 90s accords in my local yards. i know where a really nice almost complete F22a car is. can i steal that ecm and test it?
Thread Starter
Joined: Jul 2008
Posts: 4
Likes: 0
From: san bernardino, ca, us
Re: my car only runs when the "D" connector is unplugged from the ECM (MY FIRST 69)
i fixed it.
first i tried the new ecm. got nothing. i then checked the helms and it said to unplug each sensor at a time, map, egr, and tps.
i unplugged the map. car didnt start. so i then unplugged the egr and it fired right up. i turned it off and installed the map plug again and then started the car. it ran and the check engine light was off. i then plugged the egr back in and the car, starts and runs.
since i replaced the distributor yesterday i think the timing is off because its idling at 1200 rpm and drops to 1000 when placed in drive.
thank you for sharing that the egr and map share the same 5v signal. i dumped $600 into this car in worthless parts. i hope it stays running. im still getting a a code 14 when i trip the two pin connector, but the D4 light isnt flashing anymore.
first i tried the new ecm. got nothing. i then checked the helms and it said to unplug each sensor at a time, map, egr, and tps.
i unplugged the map. car didnt start. so i then unplugged the egr and it fired right up. i turned it off and installed the map plug again and then started the car. it ran and the check engine light was off. i then plugged the egr back in and the car, starts and runs.
since i replaced the distributor yesterday i think the timing is off because its idling at 1200 rpm and drops to 1000 when placed in drive.
thank you for sharing that the egr and map share the same 5v signal. i dumped $600 into this car in worthless parts. i hope it stays running. im still getting a a code 14 when i trip the two pin connector, but the D4 light isnt flashing anymore.
Thread
Thread Starter
Forum
Replies
Last Post
