DTC P0172 FUEL INJECTION SYSTEM FUNCTION (RICH SIDE) - Diagnostic Procedure (Cont'd)
EF & EC-7163flowchartDiagnostic Procedure (Cont'd)
DTC P0172 Diagnostic Procedure (Cont'd)
1
2. CHECK HEATED OXYGEN SENSOR 1 (FRONT) CIRCUIT
1. Turn ignition switch "OFF".
2. Disconnect heated oxygen sensor 1 (front) harness connector and ECM harness connector.
3. Check harness continuity between ECM terminal 12 and heated oxygen sensor 1 (front) harness connector terminal 1. Refer to wiring diagram. Continuity should exist.
4. Check harness continuity between ECM terminal 12 (or terminal 1) and ground. Continuity should not exist.
5. Also check harness for short to ground and short to power.
NG
Repair open circuit or short to ground or short to power in harness or connectors.
OK
2
3. CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-7024.
2. Install fuel pressure gauge and check fuel pressure.
At idling:
When fuel pressure regulator valve vacuum hose is connected.
Approximately 235 kPa (2.35 bar, 2.4 kg/cm^2, 34 psi)
When fuel pressure regulator valve vacuum hose is disconnected.
Approximately 294 kPa (2.94 bar, 3.0 kg/cm^2, 43 psi)
NG
4. DETECT MALFUNCTIONING PART
4. DETECT MALFUNCTIONING PART
Check the following.
- Fuel pump and circuit (Refer to EC-7236.)
- Fuel pressure regulator (Refer to EC-7025.)
Repair or replace.
OK
3
GO TO 5.
See also
EC-7024 · EC-7236 · EC-7025