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2.1K views 8 replies 3 participants last post by  Hunter62  
#1 ·
I bought a 2005 Colorado 3.5l with automatic trans. It sat for years and the owner didn’t know what was wrong with it. Right now it will not engage the starter. If I bypass the starter relay the starter will engage and crank the engine. The fuel pump is also not getting any voltage. I haven’t bypassed that relay yet. Is there something common that will affect the starter and fuel pump voltage? I checked the white wire with black stripe on the ignition switch and that does have voltage. Wasn’t sure when the other 4 striped wires should have voltage to check those. With the key turned forward, the passlock light stays lit. Is that normal? I believe the passlock only affect’s the injector voltage. Any suggestions on what to check next? When the key is turned to start, what should I check up to the starter relay and the fuel pump relay?
 
#2 ·
on my 2011 when the paslock was on, mine would not crank, period, had to wait 10 minutes then try again.

there is a way to by pass the pas lok, jumping a wire, but the red padlock stays on.

google how to bypass the paslok
 
#3 ·
I don’t think it’s the passlock, the light doesn’t blink and the motor doesn’t even turn over. I bypassed the fuel pump relay and have voltage at the fuel pump. Still stumped on what is keeping the fuel pump and starter relays from energizing. I have voltage at the ignition switch white/black wire. Does anyone had a list of what the voltages should be at the other striped wires based on the key position? Or a list of the sequence once the ignition switch is turned?
 
#4 ·
The Orange wire should have voltage all the time.
Dark Blue wire should have voltage in the Run and Start positions.
That turns on the Run/Crank relay, which sends power through fuse 23 to the Park/Neutral switch, if that's in the closed position, power goes on to the PCM to tell it that it can turn on the starter relay.
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#6 ·
Corrected the cranking issue, had a broken pink wire from the pcm to the fuse box. Engine cranks over but still have no voltage to the fuel pump. If I bypass the fuel pump relay with a wire I get voltage. Fuse is good too. Anyone know the sequence from the ignition to get voltage to the fuel pump or have a diagram? Thanks
 
#7 ·
If I posted a link it wouldn't work for you.
Here's the schematic for the fuel pump.
PCM controls the relay.
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