I have a 2004 Chevy Tahoe. Turn over, no start. No fuel p...
Responses
Jaybird61
265 days ago
Hi, my name is Jay
With key in on position and fuel pump relay removed do you have power on two terminals?
Customer
265 days ago
Removed relay, switch off. Probed terminal, turned switch on, no change in coil powerpower pin on coil side of relay shows .2 volts with key on or off
Jaybird61
265 days ago
What about getting power when cycling key on and off since this pin would only get power to relay when first cycle key or when cranking over [engine](/topics-engine-chevy/) from computer.
Customer
265 days ago
we tired cycling switch from off to on but no prime signal/powerit stays constant at the .2 volts, no change
Jaybird61
265 days ago
Are you getting any codes stored in computer or have a theft light staying on? The computer is supposed to send power to the relay to energize it and you are not getting this power from computer.
Customer
265 days ago
no codes, and no theft light.
Jaybird61
265 days ago
You wither have an issue with computer internal circuit that powers the wire or wiring issue and only way to tell which one is to use a scanner that can see if computer is activating the circuit and if not when computer is issue but if it is then may have issue with wire or fuse box connection .I would use scanner to check or if you can supply power to energize relay and see if starts and runs? I can supply you engine computer wire diagram so you can see how relay is controlled. Let me know if want this?
Customer
265 days ago
diagrams would be helpful
Jaybird61
265 days ago
Here is link to diagram. Follow green wire from fuel pump relay.
[https://www.dropbox.com/s/zjuik3p4ssitb5j/engine%20controls%20%28powertrain%20management%29%20-%202004%20tahoe.pdf?dl=0](https://www.dropbox.com/s/zjuik3p4ssitb5j/engine%20controls%20%28powertrain%20management%29%20-%202004%20tahoe.pdf?dl=0)
Customer
265 days ago
would jumping across the load side contacts for the relay cause the fuel pump to run?
Jaybird61
265 days ago
Yes but pump will all the time even with key off.
Customer
265 days ago
He did that, still no fuel pressure
Jaybird61
265 days ago
Do you have single or dual fuel tanks?
Customer
265 days ago
single
Jaybird61
265 days ago
With key off do you get power to only one terminal at relay connection?
Customer
265 days ago
the load side
Jaybird61
265 days ago
So looking at diagram you jumped power to grey wire pump side and still get no fuel pump coming on?
Customer
265 days ago
no pressure.it seems like we should start at the fuel pump correct?
Jaybird61
265 days ago
Yes jump at relay and see if getting power to pump connector. Also look at connector for signs of overheating. You may have a burned connector and bad pump.
Customer
265 days ago
OK I have a good idea where to go next. Thank you so much for you help and insight
Jaybird61
265 days ago
Your welcome. Glad to help.
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I have a 2004 Chevy Tahoe. Turn over, no start. No fuel pressure. Relay checks out, checked power going to relay. Load side power is good, but no coil side power.reads .2 volts. Is this a computer issue, or could it be anything el...
I have a 2004 Chevy Tahoe. Turn over, no start. No fuel pressure. Relay checks out, checked power going to relay. Load side power is good, but no coil side power.reads .2 volts. Is this a computer issue, or could it be anything else? Mechanic's Assistant: How many miles are on the vehicle? And when was it last serviced? 215,000 serviced at 200,000 Mechanic's Assistant: Are you fixing your Tahoe yourself? What have you tried so far? We are trying to diagnose it ourselves., We have checked relay which is fine