Runs only with scanner plugged in
06-21-2013, 09:28 PM
#1
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Runs only with scanner plugged in 99 trans am on3 70mm kit
5.3 bottom end 243 heads ls6 intake
6speed
I have had the car done for 3 weeks now and I went to wire my wideband to the EGR. So I found the 5v reference cut it and spliced in my wideband. No worrys lol I go to start the car and ....... Nothing just cranks and cranks. Acts like it has a almost dead battery the gauges sweep volt gauge on dash shows 6ish volts. I checked the battery and was looking at about 12.5 volts.(I checked with voltmeter) I even replaced to alternator exciter wire and swapped the alternator and the battery from my 2004 silverado and ended with the same results.
Now I hooked up my handheld scanner while the key was on showing about 6volts. Surprise !!!!! The second I plugged in the scanner the car just magically woke up! Dash volt gauge showed 10-12 volts. Started the car and ran great not a problem. The second I unplugged the scanner the car dies and goes back to what it was 6 volts and no starting.
The codes that are in the car are P1635, p0405, p0103.Now the P0405 is a hard code and won't go away when I erase them.They all are there only if I clear them and start the car.
Now fuses are good and the OBD2 port shows 12.5 volts.
I'm stumped other than thinking the PCM is toast......................
5.3 bottom end 243 heads ls6 intake
6speed
I have had the car done for 3 weeks now and I went to wire my wideband to the EGR. So I found the 5v reference cut it and spliced in my wideband. No worrys lol I go to start the car and ....... Nothing just cranks and cranks. Acts like it has a almost dead battery the gauges sweep volt gauge on dash shows 6ish volts. I checked the battery and was looking at about 12.5 volts.(I checked with voltmeter) I even replaced to alternator exciter wire and swapped the alternator and the battery from my 2004 silverado and ended with the same results.
Now I hooked up my handheld scanner while the key was on showing about 6volts. Surprise !!!!! The second I plugged in the scanner the car just magically woke up! Dash volt gauge showed 10-12 volts. Started the car and ran great not a problem. The second I unplugged the scanner the car dies and goes back to what it was 6 volts and no starting.
The codes that are in the car are P1635, p0405, p0103.Now the P0405 is a hard code and won't go away when I erase them.They all are there only if I clear them and start the car.
Now fuses are good and the OBD2 port shows 12.5 volts.
I'm stumped other than thinking the PCM is toast......................
06-22-2013, 08:35 AM
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Thought about that to and I'm going to look some more this afternoon. All of a sudden though? I did not touch anything but that one wire??
But I'll take a look and see what I see.
Anyone have all the grounds for the F-Body?
ThNks
But I'll take a look and see what I see.
Anyone have all the grounds for the F-Body?
ThNks
09-22-2013, 09:58 PM
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Back from the dead. So glad to see someone else has had this problem. My car will run but cuts off/ dies intermittently since engine install. I know the ground on back of head is tight, but I will be checking my wires tomorrow
