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DTC P0032: Linear Air-Fuel Ratio Sensor Heater Control Circuit High (bank 1, sensor 1)
 
 
 
 
CIRCUIT OPERATION
  • Power is supplied from the MFI relay to the right bank linear air-fuel ratio sensor heater.
  • The ECM terminal LHFR controls continuity to the right bank linear air-fuel ratio sensor heater by turning the power transistor in the ECM "ON" and "OFF".
 
 
TECHNICAL DESCRIPTION
  • The ECM checks whether the heater current is within a specified range when the heater is energized.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • Right bank linear air-fuel Ratio Sensor heater current is out of specified range.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
 
 
Check Conditions
  • More than 2 seconds have passed since the engine starting sequence was completed.
  • While the right bank linear air-fuel ratio sensor heater is on.
  • Battery positive voltage is between 11 and 16.5 volts.
Judgment Criterion
  • The right bank linear air-fuel ratio sensor heater current has continued to be higher than average 10.5 amperes for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • None
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Shorted right bank linear air-fuel ratio sensor heater circuit or connector damage.
  • Right bank linear air-fuel Ratio Sensor heater failed.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Check the right bank linear air-fuel ratio sensor.
(1) Disconnect the right bank linear air-fuel ratio sensor connector and measure at right bank linear air-fuel ratio sensor side.
(2) Measure the resistance between right bank linear air-fuel ratio sensor connector power supply line and terminal LHFR.
Standard value: 2.3 - 4.2 ohms [at 20°C (68°F)]
Is the measured resistance between 2.3 and 4.2 ohms [at 20°C (68°F)]?
Go to Step 2.
Replace the right bank linear air-fuel ratio sensor. Then go to Step 5.
 
STEP 2. Check of short circuit to power supply in power supply line between MFI relay connector and right bank linear air-fuel ratio sensor connector.
Is the harness wire in good condition?
Go to Step 3.
Repair the connector(s) or wiring harness. Then go to Step 5.
 
STEP 3. Check of short circuit to power supply in LHFR line between right bank linear air-fuel ratio sensor connector and ECM connector.
Is the harness wire in good condition?
Go to Step 4.
Repair the connector(s) or wiring harness. Then go to Step 5.
 
STEP 4. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0032 set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 5.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 5. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0032 set?
Retry the troubleshooting.
The inspection is complete.