Need Help: Fuel pump

Chevy Models Forum Sonic (Aveo)
1

Hi guys,

I am working on my nephew’s 2005 Aveo with a 1.6L engine and standard shift. The issue I’m facing is that the fuel pump won’t stay on after startup. I can activate it with my scanner, but it shuts off as soon as the command times out.

I have a few questions:

  1. Is the oil pressure sensor involved in keeping the fuel pump running after startup, or does the ECU use the ignition signal for this? I’m getting conflicting opinions.
  2. If it’s the ignition signal, does anyone know which pin on the ECU it might be?
  3. Where can I find a good shop manual for this car?

Any help would be greatly appreciated. Thanks!

2

Hey there,

It sounds like a tricky issue with the fuel pump. Here are some insights that might help you troubleshoot:

  1. Oil Pressure Sensor and Fuel Pump: The oil pressure sensor on some vehicles can be involved in keeping the fuel pump running, but in the case of the 2005 Chevy Aveo, it’s more likely that the ECU uses the ignition signal to maintain the fuel pump operation after startup. The fuel pump initially primes and then relies on signals from the ECU to keep running. This would mean that a failure in the ignition signal could cause the pump to shut off.

  2. ECU Pin for Ignition Signal: For the 2005 Aveo, the specific pin on the ECU for the ignition signal can vary. However, you can usually find this information in the wiring diagrams within the vehicle’s shop manual. These diagrams will show you the pinout for the ECU and the specific functions of each pin.

  3. Finding a Good Shop Manual:

  • Factory Service Manual (FSM): This is the most comprehensive resource and usually available for purchase through authorized dealers or online platforms.

  • Chilton or Haynes Manuals: These are more general but often have sufficient information for most repairs.

  • Online Resources: Websites like ALLDATA or Mitchell1 provide access to detailed service information and wiring diagrams, though they usually require a subscription.

Additional Tips:

  • Check all fuses and relays associated with the fuel pump.

  • Ensure that all wiring and connectors are secure and in good condition.

  • A bad crankshaft position sensor can also cause similar symptoms, so consider checking that as well.

Good luck with the repair! If you have more specific questions or need further guidance, feel free to ask.