Operation CHARM: Car repair manuals for everyone.

Fuel Injector Circuit

F: FUEL INJECTOR CIRCUIT

CAUTION:
- Check or repair only faulty parts.
- After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How to Clear Diagnostic Trouble Codes. Clearing Diagnostic Trouble Codes





WIRING DIAGRAM

8F1: CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.

Connector & terminal #1 (B 134) No.4 (+) - Chassis ground (-) #2 (B 134) No.13 (+) - Chassis ground (-) #3 (B 134) No.14 (+) - Chassis ground (-) #4 (B 134) No.15 (+) - Chassis ground (-):





2) Measure voltage between ECM connector and chassis ground on faulty cylinders.

CHECK: Is the voltage more than 10 V?

YES: Go to step 8F6.

NO: Go to step 8F2.

8F2: CHECK HARNESS BETWEEN FUEL INJECTOR AND ECM CONNECTOR.
1. Turn ignition switch to OFF.
2. Disconnect connector from fuel injector on faulty cylinders.

Connector & terminal #1 (E5) No.1 - Engine ground #2 (E16) No.1 - Engine ground #3 (E6) No.1 - Engine ground #4 (E17) No.1 - Engine ground:





3. Measure voltage between ECM connector and engine ground on faulty cylinders.

CHECK: Is the resistance less than 10 Ohms?

YES: Repair ground short circuit in harness between fuel injector and ECM connector.

NO: Go to step 8F3.

8F3: CHECK HARNESS BETWEEN FUEL INJECTOR AND ECM CONNECTOR.

Connector & Terminal #1 (B134) No.4 - (E5) No.1 #2 (B134) No.13 - (E16) No.1 #3 (B134) No.14 - (E6) No.1 #4 (B134) No.15- (E17) No.1:





Measure resistance of harness connector between ECM connector and fuel injector on faulty cylinders.

CHECK: Is the resistance less than 1 Ohm?

YES: Go to step 8F4.

NO: Repair harness and connector.

NOTE:
In this case, repair the following:
- Open circuit in harness between ECM and fuel injector connector
- Poor contact in coupling connector (B22)

8F4: CHECK FUEL INJECTOR.

Terminals No.1 - No.2:





Measure resistance between fuel injector terminals on faulty cylinder.

CHECK: Is the resistance between 5 and 20 Ohms?

YES: Go to step 8F5.

NO: Replace faulty fuel injector.

8F5: CHECK POWER SUPPLY LINE.
1. Turn ignition switch to ON.

Connector & Terminal #1 (E5) No.2 (+) - Engine Ground (-) #2 (E16) No.2 (+) - Engine Ground (-) #3 (E6) No.2 (+) - Engine Ground (-) #4 (E17) No.2 (+) - Engine Ground (-):





2. Measure voltage between fuel injector and engine ground on faulty cylinders.

CHECK: Is the voltage more than 10 V?

YES: Repair poor contact in all connectors in fuel injector circuit.

NO: Repair harness and connector.

NOTE:
In this case, repair the following:
- Open circuit in harness between main relay and fuel injector connector on faulty cylinders
- Poor contact in coupling connector (B22)
- Poor contact in main relay connector
- Poor contact in fuel injector connector on faulty cylinders

8F6: CHECK HARNESS BETWEEN FUEL INJECTOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF.

2) Disconnect connector from fuel injector on faulty cylinder.

3) Turn ignition switch to ON.

Connector & Terminal #1 (B134) No.4 (+) - Chassis Ground (-) #2 (EB134) No.13 (+) - Chassis Ground (-) #3 (134) No.14 (+) - Chassis Ground (-) #4 (B134) No.15 (+) - Chassis Ground (-):





4) Measure voltage between ECM connector and chassis ground on faulty cylinders.

CHECK: Is the voltage more than 10 V?

YES: Repair battery short circuit in harness between ECM and fuel injector. After repair, replace ECM.

NO: Go to step 8F7.

8F7: CHECK EACH FUEL INJECTOR.
1. Turn ignition switch to OFF.

Terminals No.1 - No.2:





2) Measure resistance between fuel injector terminals on faulty cylinder.

CHECK: Is the resistance less than 1 Ohm?

YES: Replace faulty fuel injector.

NO: Go to step 8F8.

8F8: CHECK POOR CONTACT.
Check poor contact in ECM connector.

CHECK: Is there poor contact in ECM connector?

YES: Repair poor contact in ECM connector.

NO: Check crankshaft position sensor circuit.