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Dan, Technician
Category: Pontiac
Satisfied Customers: 23473
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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2001 pontiac grand am: relay..fuel pump..tested..replaced fuel filter

Resolved Question:

I have 2001 pontiac grand am, and got code p0463 and p0452. I replaced the relay and pulled out fuel pump and tested it, its good. I also replaced fuel filter and still no fuel and car does nt start.I dont have a wiring diagram of the fuel system, when key is truned on I dont hear the fuel pump and I belive there are 6 wires that.
Submitted: 5 years ago.
Category: Pontiac
Expert:  Dan replied 5 years ago.
Welcome to JustAnswer, my name is XXXXX XXXXX I'm here to help get your problem resolved. Ask follow up questions, thanks. Here is a diagram of fuel pump circuits....I'd start at the relay and check for power/ground to see whats missing and go from there. Let me know if you run into questions, thanks.
Customer: replied 5 years ago.


Thanks for the diagram, My wife said the security light came when she started the car and drove it for about 20 miles then truned car off and the light stayed off. Can this be why I'm not get fuel and not starting?

Expert:  Dan replied 5 years ago.
Neither of the codes should cause this problem...These codes would be the result of pump not having power/ground...Theft light could be problem...These vehicles have alot of problems with ignition lock cylinders and passlock sensors that can cause no start issues...If check engine light was already on then its likely a security issue.

P0463 Fuel Level Sensor High Voltage
Possible CausesSetting Conditions
  • Fuel level sensor connector is damaged (inspect pins for damage, corrosion)
  • Fuel level sensor signal circuit is shorted to system voltage
  • Fuel level sensor ground circuit is open
  • Fuel level sender is damaged, binding or not aligned properly
  • PCM has failed
Engine running; and the PCM detected the Fuel Level sensor signal was more than 3.0v (98%) for 25 seconds. The fuel gauge defaults to 40% when this codes sets.

This code sets in 1 Trip(s).

P0452 Fuel Tank Pressure Sensor Circuit Low Voltage
Possible CausesSetting Conditions
  • FTP sensor connector is damaged (inspect pins for damage, and for moisture)
  • FTP sensor signal circuit is open or shorted to ground
  • FTP sensor reference (5v) circuit is open or shorted to ground
  • FTP sensor has failed
  • PCM has failed
Engine running; and the PCM detected the Fuel Tank Pressure (FTP) sensor signal circuit was less than 0.10v for 25 seconds. The FTP sensor measures the difference between the air pressure and vacuum in the EVAP system, and the outside air pressure. The PCM supplies a 5v VREF and a low reference circuit to the FTP sensor. The FTP sensor signal varies depending on EVAP system pressure or vacuum.

This code sets in 1 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)
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