[Previous][Next]
DTC P2253: Heated Oxygen Sensor Offset Circuit High Voltage
 
 

 
 
HEATED OXYGEN SENSOR OFFSET CIRCUIT HIGH VOLTAGE CIRCUIT
Refer to DTC P0137 - Heated Oxygen Sensor (rear) Circuit Low Voltage .
 
 
CIRCUIT OPERATION
Refer to DTC P0137 - Heated Oxygen Sensor (rear) Circuit Low Voltage .
 
 
TECHNICAL DESCRIPTION
  • The ECM applies an offset voltage of 0.5 volt to the heated oxygen sensor.
  • The ECM checks for heated oxygen sensor offset voltage.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • Heated oxygen sensor offset voltage is over specified range.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITION
Logic Flow Chart
 
 
Check Condition
  • More than 2 seconds have passed since the engine starting sequence was completed.
Judgment Criterion
  • Heated oxygen sensor offset voltage is more than 0.6 volt for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Does not control air-fuel ratio closed loop.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnosis Function - OBD-II Drive Cycle - Pattern 23 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Heated oxygen sensor (rear) failed.
  • Shorted heated oxygen sensor (rear) circuit or connector damage.
  • ECM failed.

 
 
DIAGNOSIS
Required Special Tools:
  • MB991958: Scan Tool (M.U.T.-III Sub Assembly)
    • MB991824: V.C.I.
    • MB991827: USB Cable
    • MB991910: Main Harness A
  • MB991658: Test Harness
  • MB992110: Power Plant ECU Check Harness
STEP 1. Check harness connector D-38 at heated oxygen sensor (rear) for damage.
Are the harness connectors in good condition?
Go to Step 2.
Repair or replace them. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 8.
 
STEP 2. Check the heated oxygen sensor (rear).
(1) Disconnect the heated oxygen sensor (rear) connector D-38 and connect test harness special tool MB991658 to the connector on the heated oxygen sensor (rear) side.
(2) Warm up the engine until engine coolant temperature reaches 80°C (176°F) or higher.
(3) Drive at 50 km/h (31mph) or more for 10 minutes.
(4) Connect a digital voltage meter between terminal No. 3 and terminal No. 4.
(5) Measure the output voltage of heated oxygen sensor under the following driving.
  • Transaxle: 2nd speed
  • Drive with wide open throttle
  • Engine: 3,500 r/min or more
(6)
Standard value: 0.6 - 1.0 V
noteIf the temperature of sensing area does not reach the high temperature [of approximately 400°C (752°F) or more] even though the heated oxygen sensor is normal, the output voltage would be possibly low in spite of the rich air-fuel ratio.
noteWhen the vehicle is driven with high loads, the temperature of the sensing area of the heated oxygen sensor is sufficiently high. Thus, it is not necessary to apply the voltage to the heater.
Is the measured voltage between 0.6 and 1.0 volt?
Go to Step 3.
Replace the heated oxygen sensor (rear). Then go to Step 8.
 
STEP 3. Check harness connector B-26 at ECM for damage.
Is the harness connector in good condition?
Go to Step 4.
Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 8.
 
STEP 4. Measure the sensor offset voltage at ECM connector B-26 by using power plant ECU check harness special tool MB992110.
(1) Disconnect all ECM connectors. Connect the power plant ECU check harness special tool MB992110 between the separated connectors.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 41 and ground.
  • Voltage should be between 0.4 and 0.6 volt.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the measured voltage between 0.4 and 0.6 volt?
Go to Step 7.
Go to Step 5.
 
STEP 5. Check for short circuit to power supply between heated oxygen sensor (rear) connector D-38 (terminal No. 4) and ECM connector B-26 (terminal No. 41).
noteCheck harness after checking intermediate connectors A-17 and C-15. If intermediate connector is damaged, repair or replace them. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 8.
Is the harness wire in good condition?
Go to Step 6.
Repair it. Then go to Step 8.
 
STEP 6. Check for short circuit to power supply between heated oxygen sensor (rear) connector D-38 (terminal No. 3) and ECM connector B-26 (terminal No. 40).
noteCheck harness after checking intermediate connectors A-17 and C-15. If intermediate connector is damaged, repair or replace them. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 8.
Is the harness wire in good condition?
Go to Step 7.
Repair it. Then go to Step 8.
 
STEP 7. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P2253 set?
Replace the ECM (Refer to, Removal and Installation ). Then go to Step 8.
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 8. 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 23 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P2253 set?
Retry the troubleshooting.
The inspection is complete.