FUEL PUMP RELAY
The Powertrain Control Module (PCM) controls fuel pump relay operation by controlling fuel pump relay ground circuit. PCM opens ground circuit when ignition is off, and completes ground circuit when ignition is on, to provide fuel pump operation. When ignition is first turned on, if engine rotation is not detected, PCM de-energizes fuel pump relay after approximately one second.
Fuel pump relay receives battery voltage from ignition switch and fuse or fusible link depending on application. Fuel pump relay is located in Power Distribution Center At Driver's Side Front Corner Of Engine
If fuel pump relay or control circuit becomes defective, a Diagnostic Trouble Code (DTC) may be stored in PCM. See TESTS W/CODES - 2.0L article for diagnosis of DTC for fuel pump relay. For additional information on diagnosis for fuel pump with fuel pump relay and control circuit, see NO START (NS-2A) TEST in TESTS W/CODES -2.0L article.
TEST NS-2A: CHECKING FUEL SYSTEM
Perform TEST DTC before proceeding.
High fuel pressure may be present in fuel lines. Open fuel system with caution.
1. Ensure throttle cables are not holding throttle open. If throttle is being held open, repair as necessary. Perform TEST VER-1A. If throttle is not being held open, go to next step.
2. Using scan tool, read Throttle Position (TP) sensor voltage. If voltage is more than 1.5 volts, go to next step. If voltage is 1.5 volts or less, go to step 4).
3. Disconnect TP sensor connector. Inspect TP sensor connector for pushed out terminals or damage. If TP sensor connector is okay, replace TP sensor. Perform TEST VER-1A. If TP sensor connector is damaged, repair as necessary. Perform TEST VER-1A.
4. If vehicle is equipped with a factory theft security system, go to next step. If vehicle is not equipped with a factory theft security system, go to step 6).
5. Using scan tool, read theft security system status. If scan tool shows fuel is on, go to next step. If scan tool does not show fuel is on, perform theft security system test. If anti-theft system article does not find a problem with theft alarm, replace Powertrain Control
Module (PCM). Perform TEST VER-1A.
6. Using scan tool, actuate ASD fuel system test. Check for fuel pump operation at fuel tank. If fuel pump operates, go to next step. If fuel pump does not operate, go to TEST NS-5A.
7. Using scan tool, stop ASD fuel system actuation. Turn ignition off. Ensure fuel tank is at least 1/4 full before performing this test. Release fuel pressure. Install fuel pressure gauge to fuel rail. Go to next step.
8. Turn ignition on. Using scan tool, actuate ASD fuel system test. Read fuel pressure gauge. If fuel pressure is within specification, ( 49 psi (338 kPa) go to next step. If fuel pressure is more than specification, perform TEST NS-4B. If fuel pressure is less than specification, perform TEST NS-4A.
9 Using scan tool, stop ASD fuel system actuation. Attempt to start vehicle. If vehicle started and stalled repeatedly, go to TEST NS-7A. If vehicle did not start and stall repeatedly, fuel pressure is okay. Go to TEST NS-3A.
Sunday, January 9th, 2011 AT 7:48 AM