Fuel pump electrical problems

Tiny
DALLAS WHITE
  • MEMBER
  • 2003 GMC SAVANA
  • 183,000 MILES
If I bypass the relay to the fuel pump should not the van start and stay running?Fuel system problems are the result of a short to ground in the ignition. Fuel pump and filter replaced. Testing relay and it is functions clicks when connected on control terminals. We can relay bypass the van will start, but will not stay running. With the relay in van will not start at all.
Thursday, January 19th, 2017 AT 6:34 PM

8 Replies

Tiny
CARADIODOC
  • MECHANIC
  • 33,870 POSTS
That relay should turn on for one second when you turn on the ignition switch. If it does, that circuit is working. If it does not turn on again during engine rotation, (cranking or running), you are missing a signal from the crankshaft position sensor or camshaft position sensor. You did not list an engine size, so I do not know which system you have.
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Thursday, January 19th, 2017 AT 6:41 PM
Tiny
WRENCHTECH
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Do you by chance have a security light on or flashing when you try to start it?
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Friday, January 20th, 2017 AT 4:22 AM
Tiny
DALLAS WHITE
  • MEMBER
  • 4 POSTS
Prodemand. Com says it is a 5.0 engine. G2500 cargo van 183000 miles. Steering column is missing. Exposed wires on the bottom of the ignition. Driver was making a right-hand turn causing the keys to connect terminals at the bottom of the ignition. The ignition fuse in the power distribution box under the hood shorted out. Fuel pump would not function when I got to the vehicle. Replace the fuse fuel pump and filter. Van will start now with fuel pump relay in but will not stay running.

Been trying to figure this out for four days now. Do not get paid until it runs.

Graduating from college for diesel and heavy equipment mechanics less than a year ago. Certificate in advanced gasoline engines. But this is driving me crazy.
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+2
Friday, January 20th, 2017 AT 5:35 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
What about the question I asked you?
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-2
Friday, January 20th, 2017 AT 5:38 PM
Tiny
DALLAS WHITE
  • MEMBER
  • 4 POSTS
There is a lit-up security light on the dash.
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Friday, January 20th, 2017 AT 5:50 PM
Tiny
WRENCHTECH
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There is an issue with the Pass-lock security system. You may have damaged the sensor or sensor wires when the keys hit the lock. You may have to replace the ignition cylinder and then do a relearn to the system. The keys do not contain transponders.

Learn procedures:
There are two available methods to perform the programming procedure:

A ten minutes procedure which requires a Tech 2 and a tech-line terminal.
A thirty minutes procedure which does not require the use of any tools.

Ten Minute Learn Procedure

Tools required:

Tech 2
Tech-line terminal with current Service Programming System (SPS) software

Connect the Tech 2 to the vehicle.
Select "Request Information" under "Service Programming".
Disconnect the Tech 2 from the vehicle and connect it to a tech-line terminal.
On the tech-line terminal, select "Theft Module Re-Learn" under "Service Programming".
Disconnect the Tech 2 from the tech-line terminal and connect it to the vehicle.
Turn ON the ignition, with the engine OFF.
Select "VTD Re-Learn" under "Service Programming".
Attempt to start the engine, then release the key to ON, vehicle will not start.
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn off, the vehicle is now ready to relearn the Pass-lock(TM) Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK.
Turn OFF the ignition, and wait five seconds.
Start the engine, the vehicle has now learned the password.
With the Tech 2 scan tool, clear any DTCs.

Thirty minute Learn Procedure

Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON, vehicle will not start.
Observe the SECURITY telltale, after approximately ten minutes the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of three cycles/thirty minutes, the vehicle is now ready to relearn the Pass-lock(TM) Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.
Start the engine. The vehicle has now learned the Pass-lock(TM) Sensor Data Code and/or password.

IMPORTANT: The vehicle learns the Pass-lock(TM) Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
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Friday, January 20th, 2017 AT 5:56 PM
Tiny
DALLAS WHITE
  • MEMBER
  • 4 POSTS
1999 GMC Sonoma 5.0 liter engine two wheel drive. Vin 1gtfg25mxx1067481. Replaced ignition cylinder tried the 30-minute learn process. Security light never goes off. Van would start briefly before ignition cylinder change. Now the van will not start even briefly with the new lock cylinder or the old lock cylinder
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Thursday, January 26th, 2017 AT 5:53 PM
Tiny
WRENCHTECH
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You may have more problems than an ignition lock that may require a professional scan tool to diagnose properly.

I would try the relearn again first.
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Thursday, January 26th, 2017 AT 5:56 PM

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