Diagnosis Procedure

FUEL PUMP


Description






The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine start ability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.









FUEL PUMP


Diagnosis Procedure

1.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
4. Check the voltage between ECM harness connector terminals.





Is the inspection result normal?
YES - GO TO 4.
NO - GO TO 2.
2.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II
Check the voltage between IPDM E/R harness connector and ground.





Is the inspection result normal?
YES - GO TO 3.
NO - GO TO 16.
3.DETECT MALFUNCTIONING PART
Check the following.
- IPDM E/R harness connector F12
- Harness for open or short between IPDM E/R and ECM
- Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK CONDENSER POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Disconnect condenser harness connector.
4. Turn ignition switch ON.
5. Check the voltage between condenser harness connector and ground.





Is the inspection result normal?
YES - GO TO 8.
NO - GO TO 5.
5.CHECK 15 A FUSE
1. Turn ignition switch OFF.
2. Disconnect 15 A fuse (No. 41).
3. Check 15 A fuse.
Is the inspection result normal?
YES - GO TO 6.
NO - Replace fuse.
6.CHECK CONDENSER POWER SUPPLY CIRCUIT-II
1. Disconnect IPDM E/R harness connector.
2. Check the continuity between IPDM E/R harness connector and condenser harness connector.





3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 16.
NO - GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E104, B4
- IPDM E/R connector E10
- Harness for open or short between IPDM E/R and condenser
- Repair open circuit or short to power in harness or connectors.
8.CHECK CONDENSER GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check the continuity between condenser harness connector and ground.





3. Also check harness for short to power.
Is the inspection result normal?
YES - GO TO 10.
NO - GO TO 9.
9.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B4, E104 (with rear view monitor)
- Harness for open or short between condenser and ground
- Repair open circuit or short to power in harness or connectors.
10.CHECK CONDENSER
Component Inspection (Condenser).
Is the inspection result normal?
YES - GO TO 11.
NO - Replace condenser.
11.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-III
1. Disconnect "fuel level sensor unit and fuel pump" harness connector.
2. Check harness continuity between IPDM E/R harness connector and "fuel level sensor unit and fuel pump" harness connector.





Is the inspection result normal?
YES - GO TO 13.
NO - GO TO 12.
12.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B4, E104
- Harness for open or short between "fuel level sensor unit and fuel pump" and IPDM E/R
- Repair open circuit or short to power in harness or connectors.
13.CHECK FUEL PUMP GROUND CIRCUIT
1. Disconnect "fuel level sensor unit and fuel pump" harness connector.
2. Check the continuity between "fuel level sensor unit and fuel pump" harness connector and ground.





Is the inspection result normal?
YES - GO TO 15.
NO - GO TO 14.
14.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B4, E104 (with rear view monitor)
- Harness for open or short between "fuel level sensor unit and fuel pump" and ground
- Repair open circuit or short to power in harness or connectors.
15.CHECK FUEL PUMP
Component Inspection (Fuel Pump).
Is the inspection result normal?
YES - GO TO 16.
NO - Replace fuel pump.
16.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
Is the inspection result normal?
YES - Replace IPDM E/R.
NO - Repair or replace harness or connectors.