Engine Controls For California

DTC P0031, P0032 A/F SENSOR 1 HEATER

Description


SYSTEM DESCRIPTION






The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating condition to keep the temperature of A/F sensor 1 element at the specified range.


CONSULT Reference Value in Data Monitor Mode

Specification data are reference values.







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 11 V at idle.
1.Start engine and run it for at least 10 seconds at idle speed.
2.Check 1st trip DTC.
3.If 1st trip DTC is detected, go to .


Wiring Diagram






Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT.

CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.







Diagnosis Procedure


1. CHECK GROUND CONNECTIONS

1.Turn ignition switch OFF.





2.Loosen and retighten ground screws on the body.
For California.
-White arrow indicates : Vehicle front
-Body ground (1)
OK or NG
OK- GO TO 2.
NG- Repair or replace ground connections.

2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT






1.Disconnect air fuel ratio (A/F) sensor 1 harness connector (1).
2.Turn ignition switch ON.
-Air fuel ratio (A/F) sensor 1 (2)





3.Check voltage between A/F sensor 1 terminal 4 and ground with
CONSULT 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 E3, F2
- 10 A fuse
- Harness for open or short between A/F sensor 1 and fuse
- Repair or replace harness or connectors.

4. CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect ECM harness connector.
3.Check harness continuity between ECM terminal 8 and A/F sensor 1 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 A/F SENSOR 1 HEATER

.
OK or NG
OK- GO TO 6.
NG- Replace air fuel ratio (A/F) sensor 1.

6. CHECK INTERMITTENT INCIDENT

Perform Initial Inspection and Diagnostic Overview
-INSPECTION END


Component Inspection


AIR FUEL RATIO (A/F) SENSOR 1 HEATER






1.Check resistance between A/F sensor 1 terminals as follows.





2.If NG, replace air fuel ratio (A/F) sensor 1.

CAUTION:
- Discard any A/F 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 A/F sensor, clean exhaust system threads using Heated Oxygen Sensor Thread Cleaner tool J43897-18 or J-43897-12 and approved anti-seize lubricant.