Up to VIn #386333

DTC P0037, P0038 HO2S2 HEATER





Description

SYSTEM DESCRIPTION





The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed, amount of intake air and engine coolant temperature.

OPERATION









CONSULT-III Reference Value in Data Monitor Mode









On Board Diagnosis Logic









DTC Confirmation Procedure

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at idle.
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to "Diagnosis Procedure".




Wiring Diagram














Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to Up to VIn #386333.





OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK HO2S2 POWER SUPPLY CIRCUIT





1. Disconnect heated oxygen sensor 2 harness connector (2).
Arrow Indicates Vehicle front
- Heated oxygen sensor 2 (1)
2. Turn ignition switch ON.





3. Check voltage between HO2S2 terminal 2 and ground with CONSULT-III or tester.

Voltage: Battery voltage

OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E8, F8
- Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 5 and HO2S2 terminal 3. Refer to Wiring Diagram.

Continuity should exist.

4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to "Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 2.
6.CHECK INTERMITTENT INCIDENT
Refer to Up to VIn #386333 Up to VIn #386333.
>> INSPECTION END




Component Inspection

HEATED OXYGEN SENSOR 2 HEATER
1. Check resistance between HO2S2 terminals as follows.





2. If NG, replace heated oxygen sensor 2.

CAUTION:
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.





- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.




Removal and Installation

HEATED OXYGEN SENSOR 2
Refer to Component Removal and Installation.