Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnosis Procedure
- CHECK FUEL INJECTOR POWER SUPPLY
- Turn ignition switch ON.
- Check the voltage between ECM harness connector and ground.
+ - Voltage ECM Connector Terminal F111 46 Ground Battery voltage 51 E80 111 112 Is the inspection result normal?
YES: GO TO 3.
NO: GO TO 2.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E46, E94, F22 or F103
- 15 A fuse (No. 87)
- 30 A fuse (No. 71)
- Harness for open or short between ECM and fuse
- Fuel injector relay. Refer to
"COMPONENT INSPECTION (FUEL INJECTOR RELAY) "
: Repair open circuit, short to ground or short to power in harness or connectors.
- CHECK FUEL INJECTOR CIRCUIT
- Turn ignition switch OFF.
- Disconnect fuel injector harness connector and ECM harness connector.
- Check the continuity between fuel injector harness connector and ECM harness connector.
Cylinder + - Continuity Fuel injector ECM Connector Terminal Connector Terminal 1 F123 1 F110 101 Existed 2 108 2 F124 1 F111 7 2 4 3 F125 1 F111 6 2 3 4 F126 1 F110 107 2 104 5 F127 1 F111 2 2 9 6 F128 1 F110 102 2 109 7 F129 1 F110 106 2 103 8 F130 1 F111 1 2 8 - Also check harness for short to ground and to power.
Is the inspection result normal?
YES: GO TO 4.
NO: Repair or replace error-detected parts.
- CHECK ECM GROUND CIRCUIT
Check the continuity between ECM harness connector and ground.
+ - Continuity ECM Connector Terminal F111 5 Ground Existed E80 114 115 Is inspection result normal?
YES: GO TO 5.
NO: Repair or replace error-detected parts.
- CHECK FUEL INJECTOR
Refer to "COMPONENT INSPECTION (FUEL INJECTOR) ".
Is the inspection result normal?
YES: Check intermittent incident. Refer to "INTERMITTENT INCIDENT ".
NO: Replace malfunctioning fuel injector. Refer to "REMOVAL AND INSTALLATION ".
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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