Circuit/System Testing

NOTE:

Verify the fuel system for damage or external leaks before proceeding.
Verify that an adequate amount of fuel is in the fuel tank before proceeding.
Do not start the engine.
Before proceeding with this test review the CH 48027 user manual for safety information and instructions.

Ignition ON.
Verify that the A7 Fuel Pump and Level Sensor Assembly turns on & off when commanding the Fuel Pump Relay ON and OFF with a scan tool.
- If the fuel pump does not run
  Refer to Fuel Pump Electrical Circuit Diagnosis .
- Go to next step: If the fuel pump runs but engine does not run
Ignition OFF, all accessories OFF, install J 42982 then CH 48027 .
Ignition ON.
Verify that the fuel pressure is between 345 - 414 kPa (50 - 60 PSI) and does not decrease more than 34 kPa (5 PSI) in 5 min. when commanding the Fuel Pump Relay ON and OFF with a scan tool.
- If greater than 345 - 414 kPa (50 - 60 PSI)
  Replace the A7 Fuel Pump and Level Sensor Assembly.
- If less than 345 - 414 kPa (50 - 60 PSI)
1. Ignition OFF.
2. Verify for the following conditions:
  - Restricted fuel feed pipe
  - Restricted or clogged strainer
  - The A7 Fuel Pump and Level Sensor Assembly harness connectors and the ground circuits for poor connections.
- If the pressure decreases more than 34 kPa (5 PSI) in 5 min.
1. Ignition OFF.
2. Verify the following conditions do not exist:
  - Leaking fuel injector
  - Stuck open fuel pressure regulator
  - If any condition exist, repair as necessary.
- Go to next step: If between 345 - 414 kPa (50 - 60 PSI) and does not decrease more than 34 kPa (5 PSI) in 5 min
Verify that the fuel injectors work correctly.
- If the fuel injectors do not work correctly.
  Refer to Fuel Injector Diagnosis .
- Go to next step: If the fuel injectors are working correctly.
All OK.