daul fans won't work until i use this why
02-20-2017, 04:26 PM
#1
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Car: 1989 camaro iroc
Engine: 350 tpi
Transmission: auto
Axle/Gears: 323
daul fans won't work until i use this why
fans don't work until i plug this old ecm scanner . i plug it in and i saw the fan come on . i wont to know how to read this because i i do not have instruction why does this make my fan come on . need info
02-20-2017, 06:22 PM
#2
Re: daul fans won't work until i use this why
When you connect your scanner, or jumper pins A & B together, you're telling the computer to go into diagnostic mode. It's normal for the fan to come on during diagnostics.
No need for a scanner, slip a paperclip, or piece of wire between pins A and B, turn the key to run (not start) and watch the service engine light. It'll flash once, short pause, then flash twice, that's a code 12 to let you know the ECM is in diagnostic mode. It'll repeat that 12 two or three times, then it'll start flashing any other stored codes. Three fast flashes followed by a short pause and two more fast flashes would be a 32, etc. Each code repeats 3 times and then it moves to the next code. When it shows 12 again it's finished. If you get code 12 4 times in a row, there are no stored fault codes.
No need for a scanner, slip a paperclip, or piece of wire between pins A and B, turn the key to run (not start) and watch the service engine light. It'll flash once, short pause, then flash twice, that's a code 12 to let you know the ECM is in diagnostic mode. It'll repeat that 12 two or three times, then it'll start flashing any other stored codes. Three fast flashes followed by a short pause and two more fast flashes would be a 32, etc. Each code repeats 3 times and then it moves to the next code. When it shows 12 again it's finished. If you get code 12 4 times in a row, there are no stored fault codes.