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Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ensure battery is fully charged and that there is enough fuel in fuel tank. If engine is operational, go to next step. If engine is not operational, remove cap on fuel pressure test port, located on fuel rail. Turn ignition on. Slightly depress Schrader valve and note if fuel is present. If fuel is under pressure, go to next step. If fuel is not present, check fuel pump operation or circuit. Repair as necessary.
  2. Turn ignition off. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE  . Connect Fuel Gauge Pressure Adapter (309725) and Fuel Pressure Gauge (SA9127E) to fuel pressure test port. Install scan tool. Turn ignition on, with engine off. Using scan tool, command FUEL PUMP on. Check and record fuel pressure gauge reading. Repeat at least 2 times. If fuel pressure is less than 50 psi (345 kPa), go to next step. If fuel pressure is 50-60 (345-414 kPa), go to step  11 . If fuel pressure is greater than 60 psi (414 kPa), go to step  16 .
  3. Turn ignition off. Release fuel pressure. Remove fuel line retainer clip from fuel feed line to fuel rail transfer line. Using a Fuel Line Separator (J37088A), disconnect fuel feed at fuel rail transfer line. Connect inlet side of Fuel Flow/Pressure Test Adapter (SA9127E-7) into fuel feed line quick connect. Ensure fitting is firmly latched. Connect fuel pressure gauge to test adapter. Connect fuel flow/pressure test adapter outlet end to a fuel return hose and place other end into an approved gasoline container.
  4. Turn on fuel flow/pressure test adapter valve. Turn ignition on. Using scan tool, energize fuel pump for 10 seconds. Repeat 2 times. Record fuel pressure. If fuel pressure is greater than 50 psi (345 kPa), check for faulty fuel rail and injectors. If fuel pressure is less than 50 psi (345 kPa), go to next step.
  5. Turn ignition off. Release fuel pressure. Disconnect fuel feed line at fuel filter outlet. Fuel filter is located under the vehicle, near fuel tank. Connect inlet side of fuel flow/pressure adapter onto fuel filter outlet quick connect. Ensure fitting is firmly latched. Connect fuel pressure gauge to test adapter. Connect fuel flow/pressure adapter outlet end to a return hose and place other end of hose into an approved gasoline container.
  6. Turn on fuel flow/pressure test adapter valve. Turn ignition on. Using scan tool, energize fuel pump for 10 seconds. Repeat 2 times. Record fuel pressure. If fuel pressure is greater than 50 psi (345 kPa), replace fuel line in chassis bundle. If fuel pressure is less than 50 psi (345 kPa), go to next step.
  7. Turn ignition off. Release fuel pressure. Disconnect fuel feed line and return line from fuel filter inlet. Connect inlet side of fuel flow/pressure adapter into fuel feed line quick connect. Ensure fitting is firmly latched. Connect fuel pressure gauge to test adapter. Connect fuel flow/pressure adapter outlet end to fuel return line.
  8. Turn on fuel flow/pressure test adapter valve. Turn ignition on. Using scan tool, energize fuel pump for 10 seconds. Repeat 2 times. Record fuel pressure. If fuel pressure is greater than 50 psi (345 kPa), replace fuel filter. If fuel pressure is less than 50 psi (345 kPa), go to next step.
  9. Turn ignition off. Release fuel pressure. Disconnect fuel feed line at fuel filter inlet. Connect inlet side of fuel flow/pressure adapter into fuel feed line quick connect. Ensure fitting is firmly latched. Connect fuel pressure gauge to test adapter. Connect fuel flow/pressure adapter outlet end to fuel return line or fuel return hose, and place other end of hose into an approved gasoline container.
  10. Turn on fuel flow/pressure test adapter valve. Turn ignition on. Using scan tool, energize fuel pump for 10 seconds. Repeat 2 times. Record fuel pressure. If fuel pressure is greater than 72 psi (496 kPa), regulator is faulty. Replace secondary fuel pump module. If fuel pressure is less than 72 psi (496 kPa), replace secondary fuel pump module.
  11. Turn ignition off. Release fuel pressure. Connect Gauge Bar Set (SA9127E) and pressure gauge to fuel pressure test port. Turn ignition on. Using scan tool, energize fuel pump for 10 seconds. Record fuel pressure. Turn off fuel pump. Wait 5 minutes. Record fuel pressure and subtract from previous reading. Repeat test 2 times. If pressure decay is less than 8 psi (55 kPa) in 5 minutes, check for faulty fuel injectors. If pressure decay is greater than 8 psi (55 kPa) in 5 minutes, go to next step.
  12. Turn ignition off. Release fuel pressure. Disconnect fuel feed line at fuel rail. Connect Fuel Flow/Pressure Test Adapter (SA9127E-7) into fuel feed line quick connect. Ensure fitting is firmly latched. Connect fuel pressure gauge to test adapter. Connect fuel flow/pressure test adapter outlet end to a fuel return hose and place other end into an approved gasoline container.
  13. Turn off fuel flow/pressure test adapter valve. Turn ignition on. Using scan tool, energize fuel pump for 10 seconds. Record fuel pressure. Turn off fuel pump. Wait 5 minutes. Record fuel pressure and subtract from previous reading. Repeat test 2 times. If pressure decay is less than 8 psi (55 kPa) in 5 minutes, check for leaky injectors. If pressure decay is greater than 8 psi (55 kPa), go to next step.
  14. Turn ignition off. Release fuel pressure. Disconnect fuel feed line from fuel filter inlet. Connect inlet side of Fuel Flow/Pressure Adapter (SA9127E-7) into fuel feed line quick connect. Ensure fitting is firmly latched. Connect fuel pressure gauge to test adapter. Connect fuel flow/pressure test adapter outlet end to a fuel return hose and place other end into an approved gasoline container.
  15. Turn on fuel flow/pressure test adapter valve. Turn ignition on. Using scan tool, energize fuel pump for 10 seconds. Cycle test adapter valve on and off at least 2 times within 10 seconds. Record fuel pressure. Turn off fuel pump. Wait 5 minutes. Record fuel pressure and subtract from previous reading. Repeat test 2 times. If pressure decay is less than 8 psi (55 kPa) in 5 minutes, regulator is faulty. Replace secondary fuel pump module. Refer to appropriate REMOVAL & INSTALLATION - VUE article. If pressure decay is greater than 8 psi (55 kPa), replace primary fuel pump.
  16. Turn ignition off. Raise and support vehicle. Remove fuel tank. Check fuel return line from fuel filter to secondary fuel pump module. If fuel line is plugged or crimped, replace fuel line. If fuel line is okay, pressure regulator is faulty. Replace secondary fuel pump module.
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