2018 / ECLIPSE CROSS / EC - Workshop Manual
13 -FUEL > 13A-DIRECT INJECTION AND MULTIPOINT FUEL INJECTION (DI AND MPI) > TROUBLESHOOTING > DIAGNOSIS CODE PROCEDURES > CODE NO. P2237 LINEAR A/F SENSOR LP+ CIRCUIT (OPEN)
Code No. P2237: Linear A/F Sensor Lp+ Circuit (open)
OPERATION
The linear A/F sensor and the engine-ECU are connected by the following 3 lines to detect the air-fuel ratio.
- The line between the linear A/F sensor and the engine-ECU connector terminal LPFL detects the air-fuel ratio.
- The auxiliary line between the linear A/F sensor and the engine-ECU connector terminal LSFL detects the air-fuel ratio.
- The line between the linear A/F sensor and the engine-ECU connector terminal LEFL is connected to earth.
FUNCTION
- The engine-ECU effects air/fuel ratio feedback control in accordance with the signals from the linear A/F sensor.
- If the linear A/F sensor has deteriorated, corrections will be made by the oxygen sensor (rear).
TROUBLE JUDGEMENT
Check Conditions
- Battery positive voltage is more than 10 V and is less than 16.5 V.
- More than 220 seconds have passed since the engine starting sequence was completed.
Judgement Criteria
- The negative circuit voltage subtracted from the pumping circuit voltage is be lower than -2.1 V or higher than 2.3 V for 2 seconds.
- The pumping current is 0 mA for 2 seconds.
FAIL-SAFE AND BACKUP FUNCTION
- Does not control air-fuel ratio closed loop.
PROBABLE CAUSES
- Failed linear A/F sensor
- Open circuit in linear A/F sensor circuit or loose connector contact
- Failed engine-ECU
DIAGNOSIS PROCEDURE
STEP 1. Check of open circuit in LPFL line between linear A/F sensor connector and engine-ECU connector.
Is the check result normal?
Go to Step 2.
Repair the connector(s) or wiring harness.
STEP 2. Replace the linear A/F sensor
- After replacing the linear A/F sensor, reconfirm whether the diagnosis code is set.
Is the diagnosis code set?
Replace the engine-ECU. Check end.
