no power to ecu, tired of searching
03-22-2010, 09:03 PM
#1
Launching!
Thread Starter
iTrader: (13)
Join Date: Feb 2006
Location: tulsa, oklahoma
Posts: 226
Likes: 0
Received 0 Likes
on
0 Posts
no power to ecu, tired of searching im working on a 69 model GMC pickup with a stock ls1 in it. ive got the engine wiring an the ecu. had the ecu check an the security turn off. i dont have a home computer so i dont have much time to search all night, sorry. please help
so far i got the two battery positive voltage(pin#20-57) going to my battery an the two 12volt reference(pin#2-39) going to the ign.key. but it seems as though the computer isnt getting any power.
the pink wire ign.1 voltage(pin#19) isnt getting any power either.
all my grounds are hooked up, ive check those. and ive got it to crank over just fine just no power to the ecu. what im i missing here?
so far i got the two battery positive voltage(pin#20-57) going to my battery an the two 12volt reference(pin#2-39) going to the ign.key. but it seems as though the computer isnt getting any power.
the pink wire ign.1 voltage(pin#19) isnt getting any power either.
all my grounds are hooked up, ive check those. and ive got it to crank over just fine just no power to the ecu. what im i missing here?
03-22-2010, 09:19 PM
#2
If it's 99-02 f-body pcm, you need Battery power to C1 pin's 20 & 57. Ignition power to
C1 pin 19. You also need ignition power to the two pink wires that power the coils and injectors. One pink wire will power all of the odd numbers and one for the even numbers, as in cylinder numbers. I don't have the schematics in front of me right now, but I think there is at least one more that has to have ignition power. Possibly for the MAF. Make sure that the wire you use for ignition power stays hot while cranking. It seems to be a common problem, that people hook to a wire that's hot until they hit the starter, then it loses power.
C1 pin 19. You also need ignition power to the two pink wires that power the coils and injectors. One pink wire will power all of the odd numbers and one for the even numbers, as in cylinder numbers. I don't have the schematics in front of me right now, but I think there is at least one more that has to have ignition power. Possibly for the MAF. Make sure that the wire you use for ignition power stays hot while cranking. It seems to be a common problem, that people hook to a wire that's hot until they hit the starter, then it loses power.
03-24-2010, 12:21 PM
#3
Launching!
Thread Starter
iTrader: (13)
Join Date: Feb 2006
Location: tulsa, oklahoma
Posts: 226
Likes: 0
Received 0 Likes
on
0 Posts
does the pin 19(pink wire) need to just have one volt going to it, an how or what would i hook this up to.
ive got the pins 20 an 57 hook up to the battery an the pins 2 an 39 hook up to the ignition switch
ive seen some schematics of the wiring layout but i cant understand them or i just dont know really what im looking at.
thanks for you help
ive got the pins 20 an 57 hook up to the battery an the pins 2 an 39 hook up to the ignition switch
ive seen some schematics of the wiring layout but i cant understand them or i just dont know really what im looking at.
thanks for you help
03-24-2010, 01:38 PM
#4
19 has to have 12 volts, ignition source going to it. Find a spot on your fuse box(there are usually open terminals) that is hot with the ignition switch on and also in the start position. Make sure it has 12 volts when your in the start position also.
03-27-2010, 07:20 PM
#5
Launching!
Thread Starter
iTrader: (13)
Join Date: Feb 2006
Location: tulsa, oklahoma
Posts: 226
Likes: 0
Received 0 Likes
on
0 Posts
yeah i did that, but i still have no power to the pcm. the wires that go into the firewall, what do they need to go to. tthese wires are on my wiring harness and have to plugs on them. should one of them have power going to it so the pcm will turn on???
05-10-2010, 12:36 PM
#7
TECH Regular
iTrader: (4)
Join Date: Jun 2009
Location: st. paul mn.
Posts: 423
Likes: 0
Received 0 Likes
on
0 Posts
check your ign. wire sorce the wire that I used on my belair was hot when ign. was on but not while cranking. switched to the hot wire while cranking and bingo.alot of frusteration and a few choice words but its all good now.
Trending Topics
05-11-2010, 05:47 PM
#10
Launching!
Thread Starter
iTrader: (13)
Join Date: Feb 2006
Location: tulsa, oklahoma
Posts: 226
Likes: 0
Received 0 Likes
on
0 Posts
sorry guys i have it running now. for some time now ive had it running it just wont stay running when its under a load.
ive posted some new threads on this.
thanks for your help guys
ive posted some new threads on this.
thanks for your help guys
08-24-2020, 10:09 AM
#11
Teching In
Join Date: Aug 2020
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
240z LS1 from a 2001 trans am 5.7 ECU getting no power HELP please....
Hey guys I was surfing the web for some help and came across this thread because of a similar problem.
Last week I was driving on the freeway about 70mph for a good 30 min. When I took the exit off the freeway I stopped at the stop light and the engine started to pulse from 500 rm 1100 rpm then when I gave it some gas, it rev'd up for about half a second but would not move forward. Then I could hear the Fuel Pump going in and out of power until the car just died on me. When I tried starting her up again the fuel pump engaged then sounded like it was losing power and then just shut off completely.
Thinking it was the fuel pump....
Towed it home to find out that the Fuel pump was okay (did a bypass straight to the battery). I then checked the positive and grounds to the pump and they were good.
- Checked the fuses and relay to fuel pump (good)
- Checked to power going fuel pump fuse with accessory power engaged (no power)
- I also use an OBD2 bluetooth connector for my gauges and diagnostics but now its not getting any signal/power to the device.
Im no mechanic but I can get by where I can. Please if you have any input let me know
I want my baby running again
Hey guys I was surfing the web for some help and came across this thread because of a similar problem.
Last week I was driving on the freeway about 70mph for a good 30 min. When I took the exit off the freeway I stopped at the stop light and the engine started to pulse from 500 rm 1100 rpm then when I gave it some gas, it rev'd up for about half a second but would not move forward. Then I could hear the Fuel Pump going in and out of power until the car just died on me. When I tried starting her up again the fuel pump engaged then sounded like it was losing power and then just shut off completely.
Thinking it was the fuel pump....
Towed it home to find out that the Fuel pump was okay (did a bypass straight to the battery). I then checked the positive and grounds to the pump and they were good.
- Checked the fuses and relay to fuel pump (good)
- Checked to power going fuel pump fuse with accessory power engaged (no power)
- I also use an OBD2 bluetooth connector for my gauges and diagnostics but now its not getting any signal/power to the device.
Im no mechanic but I can get by where I can. Please if you have any input let me know
I want my baby running again
