Fuel Pump Circuit Troubleshooting (1.5 L Engine)
Fuel Pump Circuit Troubleshooting
If you suspect a problem with the fuel pump, check that the fuel pump actually runs; when it is on, you will hear some noise if you listen to the fuel fill port. The fuel pump should run for 2 seconds when the vehicle is turned to ON mode. If the fuel pump does not make noise, check as follows:
- Determine possible failure area (FI MAIN RLY OUT line, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove PGM-FI main relay 2 .
-3. Turn the vehicle to the ON mode.
-4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode PGM-FI main relay 2: disconnected Test point 1 PGM-FI main relay 2 4P socket (female terminals) No. 3: Test point 2 Body ground Is there battery voltage?
YES
Go to step 3.
NO
Go to step 2.
- Open wire check (FI MAIN RLY OUT line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Relay circuit board connector C (18P) -3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PGM-FI main relay 2: disconnected Relay circuit board connector C (18P): disconnected Test point 1 Relay circuit board connector C (18P) (female terminals) No. 17: Test point 2 PGM-FI main relay 2 4P socket (female terminals) No. 3: Is there continuity?
YES
Remove and test the relay circuit board , and replace it if needed.
NO
Repair an open in the FI MAIN RLY OUT wire between the relay circuit board and PGM-FI main relay 2.
- Open wire check (IG1 FUEL PUMP line)
-1. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode PGM-FI main relay 2: disconnected Test point 1 PGM-FI main relay 2 4P socket (female terminals) No. 1: Test point 2 Body ground Is there battery voltage?
YES
Go to step 4.
NO
Check the No. D8 (15 A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair an open in the IG1 FUEL PUMP wire between the No. D8 (15 A) fuse and PGM-FI main relay 2. If needed, replace the under-dash fuse/relay box .
- Open wire check (FUEL PUMP RLY CL- line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Jump the SCS line with the HDS, and wait more than 1 minute.
-3. Disconnect the following connector.
PCM connector A (50P) -4. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PGM-FI main relay 2: disconnected PCM connector A (50P): disconnected Test point 1 PGM-FI main relay 2 4P socket (female terminals) No. 4: Test point 2 PCM connector A (50P) No. 11 Is there continuity?
YES
The FUEL PUMP RLY CL- wire is OK. Go to step 5.
NO
Repair an open in the FUEL PUMP RLY CL- wire between the PCM (A11) and PGM-FI main relay 2.
- Determine possible failure area (PGM-FI main relay 2, others)
-1. Reinstall PGM-FI main relay 2.
-2. Connect terminals A and B with a jumper wire.
Terminal A PCM connector A (50P) No. 5 Terminal B Body ground -3. Turn the vehicle to the ON mode.
-4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode PCM connector A (50P): disconnected PCM connector A (50P) No. 5: jumped to body ground Test point 1 PCM connector A (50P) No. 11 Test point 2 Body ground Is there battery voltage?
YES
Go to step 6.
NO
Replace PGM-FI main relay 2.
- PCM operation check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove PGM-FI main relay 2 .
-3. Remove the jumper wire from PCM connector A (50P).
-4. Reconnect PCM connector A (50P).
-5. Exit the SCS mode with the HDS.
-6. Turn the vehicle to the ON mode, and measure the voltage between test points 1 and 2.
Test condition Within 2 seconds after turning vehicle to ON mode PGM-FI main relay 2: disconnected Test point 1 PGM-FI main relay 2 4P socket (female terminals) No. 3: Test point 2 PGM-FI main relay 2 4P socket (female terminals) No. 4: Is there battery voltage?
YES
Go to step 7.
NO
Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If the symptom/indication goes away and the PCM was substituted, replace the original PCM .
- Determine possible failure area (FUEL PUMP RLY OUT line, GND line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Fuel tank unit 4P connector -3. Reinstall PGM-FI main relay 2.
-4. Turn the vehicle to the ON mode, and measure the voltage between test points 1 and 2.
Test condition Within 2 seconds after turning vehicle to ON mode Fuel tank unit 4P connector: disconnected Test point 1 Fuel tank unit 4P connector (female terminals) No. 1: Test point 2 Body ground Is there battery voltage?
YES
Go to step 9.
NO
Go to step 8.
- Open wire check (FUEL PUMP RLY OUT line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove PGM-FI main relay 2.
-3. Connect terminals A and B with a jumper wire.
Terminal A PGM-FI main relay 2 4P socket (female terminals) No. 1: Terminal B PGM-FI main relay 2 4P socket (female terminals) No. 2: -4. Turn the vehicle to the ON mode.
-5. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Fuel tank unit 4P connector: disconnected PGM-FI main relay 2 :disconnected PGM-FI main relay 2 4P socket No. 1 and No. 2: jumped Test point 1 Fuel tank unit 4P connector (female terminals) No. 1: Test point 2 Body ground Is there battery voltage?
YES
The FUEL PUMP RLY OUT wire is OK. Replace PGM-FI main relay 2.
NO
Repair an open in the FUEL PUMP RLY OUT wire between PGM-FI main relay 2 and the fuel tank unit.
- Open wire check (GND line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Fuel tank unit 4P connector: disconnected Test point 1 Fuel tank unit 4P connector (female terminals) No. 3: Test point 2 Body ground Is there continuity?
YES
The GND wire is OK. Replace the fuel pump .
NO
Repair an open in the GND wire between the fuel tank unit and G503.