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Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 5575
Experience:  ASE master tech for 40 years
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Have a 1997 blazer 4.3 no spark no injector pulse no check

Customer Question

have a 1997 blazer 4.3 no spark no injector pulse no check engine light and cant communicate with scanner
Submitted: 1 year ago.
Category: Chevy
Expert:  Roy replied 1 year ago.

good morning my name is ***** ***** I will assist

check all fuses with a test light to be sure there is power and no blown fuses. no check engine light and no communication is an indication of a failed pcm.

Roy

Customer: replied 1 year ago.
new pcm crank sensor cam sensor ignition module and all fuses good thought maybe defective pcm so installed another one and same problem also new ignition switch
Expert:  Roy replied 1 year ago.

ok, did you have the new pcm flashed?? the new ones comes with no information and must be flashed

Roy

Customer: replied 1 year ago.
pcm was flashed
Expert:  Roy replied 1 year ago.

have you checked for power to the pcm??? see if any of the connectors have power with key on??

Roy

Customer: replied 1 year ago.
have power to color connectors not to small two wire connector on pcm
Expert:  Roy replied 1 year ago.

ok, pick the tps and check and see if you have a 5 volt reference voltage

Roy

Customer: replied 1 year ago.
nothing at tps
Expert:  Roy replied 1 year ago.

ok, no reference voltage indicates the pcm is not working. it should send out this voltage. hard to believe but it sounds like you have a bad pcm.

are these from the dealer or aftermarket part stores??

Roy

Customer: replied 1 year ago.
both gm dealer
Expert:  Roy replied 1 year ago.

then there must be an issue with the flashing. you may need to take it to a shop or the dealer to have the truck flashed. I have seen in the past that flashing by vin does not take and must be done when installed in the truck

Roy

Customer: replied 1 year ago.
i dont think ecm is getting powrer
Expert:  Roy replied 1 year ago.

you just told me that it had power and all fuses good???

I will see if I can get a connector view

did you view the diagram I sent you

Roy

Customer: replied 1 year ago.
looking at it now connector view will be helpful
Expert:  Roy replied 1 year ago.

check the power wires at the connectors listed that I sent you in these diagrams

Roy

Expert:  Roy replied 1 year ago.

power from fuse box to connectors

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