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.
Diagnostic Procedure
- CHECK EXHAUST GAS LEAK
- Start engine and run it at idle.
- Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK : GO TO 2.
NG : Repair or replace.
- CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK : GO TO 3.
NG : Repair or replace.
- CHECK AIR FUEL RATIO (A/F) SENSOR 1 INPUT SIGNAL CIRCUIT
- Turn ignition switch OFF.
- Disconnect corresponding air fuel ratio (A/F) sensor 1 harness connector.
- Disconnect ECM harness connector.
- Check harness continuity between the following terminals. Refer to Wiring Diagram.TERMINALS REFERENCE
A/F sensor 1 terminal ECM terminal Bank 1 1 16 2 75 5 35 6 56 Bank 2 1 76 2 77 5 57 6 58 Continuity should exist.
- Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.TERMINALS REFERENCE
Bank 1 Bank 2 A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 1 16 1 76 2 75 2 77 5 35 5 57 6 56 6 58 Continuity should not exist.
- Also check harness for short to power.
OK or NG
OK : GO TO 4.
NG : Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK FUEL PRESSURE
- Release fuel pressure to zero. Refer to "FUEL PRESSURE RELEASE ".
- Install fuel pressure gauge and check fuel pressure. Refer to
"FUEL PRESSURE CHECK
".
At idling: 350 kPa (3.57 kg/cm 2 , 51 psi)
OK or NG
OK : GO TO 6.
NG : GO TO 5.
- DETECT MALFUNCTIONING PART
Check the following.
- Fuel pump and circuit (Refer to "FUEL PUMP ".)
- Fuel pressure regulator (Refer to
"FUEL PRESSURE CHECK
".)
: Repair or replace.
- CHECK MASS AIR FLOW SENSOR
With CONSULT-II
- Install all removed parts.
- Check "MASS AIR FLOW" in "DATA MONITOR" mode with CONSULT-II.
2.0 - 6.0 g.m/sec: at idling
7.0 - 20.0 g.m/sec: at 2, 500 RPM
With GST
- Install all removed parts.
- Check mass air flow sensor signal in "Service $01" with GST.
2.0 - 6.0 g.m/sec: at idling
7.0 - 20.0 g.m/sec: at 2, 500 RPM
OK or NG
OK (With CONSULT-II) : GO TO 7.
OK (Without CONSULT-II) : GO TO 8.
NG : Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to "DTC P0102, P0103 MAF SENSOR ".
- CHECK FUNCTION OF FUEL INJECTOR-I
With CONSULT-II
- Start engine.
- Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-II.
- Make sure that each circuit produces a momentary engine speed drop.
OK or NG
OK : GO TO 10.
NG : Perform trouble diagnosis for "FUEL INJECTOR ".
- CHECK FUNCTION OF FUEL INJECTOR-I
Without CONSULT-II
- Turn ignition switch OFF.
- Disconnect harness connectors F21, F201 (bank 1) and F41, F221 (bank 2).
- Turn ignition switch ON.
- Check voltage between the following; harness connector F21 terminal 5 and ground, harness connector F41 terminal 5 and ground with CONSULT-II or tester.
Voltage: Battery voltage
- Turn ignition switch OFF.
- Disconnect ECM harness connector.
- Check harness continuity between the following terminals.TERMINALS REFERENCE
Cylinder Harness connector terminal ECM terminal 1 F21 terminal 3 23 3 F21 terminal 2 22 5 F21 terminal 1 21 7 F21 terminal 6 44 2 F41 terminal 3 42 4 F41 terminal 2 41 6 F41 terminal 1 40 8 F41 terminal 6 63 Continuity should exist.
- Also check harness for short to ground and short to power.
OK or NG
OK : GO TO 9.
NG : Perform trouble diagnosis for "FUEL INJECTOR ".
- CHECK FUNCTION OF FUEL INJECTOR-II
Provide battery voltage between the following terminals, and then interrupt it. Listen to each fuel injector operating sound.
TERMINALS REFERENCECylinder Harness connector terminal (+) (-) 1 F201 5 3 3 2 5 1 7 6 2 F221 5 3 4 2 6 1 8 6 Operating sound should exist.
OK or NG
OK : GO TO 10.
NG : Perform trouble diagnosis for "FUEL INJECTOR ".
- CHECK FUEL INJECTOR
- Turn ignition switch OFF.
- Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
- Remove fuel tube assembly. Refer to "FUEL INJECTOR AND FUEL TUBE ". Keep fuel hose and all fuel injectors connected to fuel tube.
- Disconnect all fuel injector harness connectors.
- Disconnect all ignition coil harness connectors.
- Prepare pans or saucers under each fuel injectors.
- Crank engine for about 3 seconds.
Make sure fuel does not drip from fuel injector.
OK or NG
OK (Does not drip.) : GO TO 11.
NG (Drips.) : Replace the fuel injectors from which fuel is dripping. Always replace O-ring with new one.
- CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
: INSPECTION END
NO RELATED
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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.