3.
Is the problem found?
▶ Repair the trouble causing part and go to "Verification of Vehicle Repair".
▶ Go to "Power Circuit Inspection".
Lambda sensor installed at exhaust manifold is planar ZrO2 dual cell type and it senses O2 density of exhaust gas for accurate EGR control through fuel correction. It also limits smoke which is generated by reach air-fuel mixture at engine maximum loading condition. ECM controls pumping current in order to fit λ-value from linear O2 sensor to 1.0.
Lean air-fuel mixture(1.0<λ<1.1) : ECM supplies pumping current to Lambda sensor (+pumping current) and activates it for Lambda sensor to have the characteristic at λ=1.0 (0.0 pumping current). With the value of pumping current supplied to Lambda sensor, ECM detects O2 density of exhaust gas.
Rich air-fuel mixture(0.9<λ<1.0) : ECM takes away pumping current from O2 sensor (-pumping current) and deactivates it for Lambda sensor to have the characteristic at λ=1.0 (0.0 pumping current). With the value of pumping current taken away from Lambda sensor, ECM detects O2 density of exhaust gas.
This performance is the most active and fast at normal operating temp.(450℃~600℃) thus, in order to reach normal operating temp. and last at that temp., heater(heating coil) is integrated with Lambda sensor.Heater coil is controlled by ECM as PWM. the resistance of heater coil is low when coil is cold thus, current through it increases while resistance is high when coil is hot thus, current decreases. With this principle, Lambda sensor temp. is measured and Lambda sensor heater operation varies based on the data.
P0032 is set when short to battery in Lambda sensor control circuit is detected for more than 5 sec. at Lambdasensor heater control condition. This code is due to 1)short to battery in heater control circuit or 2)Lambda sensor heater internal open.
Item | Detecting Condition | Possible Cause | ||
DTC Strategy | ● Voltage monitoring | ● Lambda sensor heater circuit ● Lambda sensor component | ||
Enable Conditions | ● Engine running | |||
Threshold Value | ● Short to battery in Lambda sensor heater control circuit | |||
Diagnostic Time | ● 5 sec. | |||
Fail Safe | Fuel cut | NO | ||
EGR Off | NO | |||
Fuel Limit | NO | |||
Check Lamp | NO | |||
Temperature (℃) | Heater resistance (Ω) | Temperature (℃) | Heater resistance (Ω) | Heater Operation Frequency |
20 | 9.2 | 400 | 17.7 | 100 Hz |
100 | 10.7 | 500 | 19.2 | |
200 | 13.1 | 600 | 20.7 | |
300 | 14.6 | 700 | 22.5 |
Electrical systems consist of a lot of harness and connectors, poor connection of terminals can cause various problems and damge of component.
Perform checking procedure as follows.
Check damage of harness and terminals : Check terminals for contact resistance, corrosion and deformation.
Check connecting condition of ECM and component connector : Check terminal seperation, damage of locking device and connecting condition between terminal and wiring.
Disconnect the pin which requires checking at male connector and insert it to the terminal at female connector for checking connecting condition. ( after checking, reconnect the pin at correct position. )
Is the problem found?
▶ Repair the trouble causing part and go to "Verification of Vehicle Repair".
▶ Go to "Power Circuit Inspection".
IG KEY "OFF", ENGINE "OFF".
Disconnect Lambda sensor connector.
IG KEY "ON".
Measure the voltage of Lambda sensor connector terminal 2.
Specification : 11.0V~13.0V ( Main relay ON power )
Is the measured voltage within the specification?
▶ Go to "Control Circuit Inspection".
▶ Repair open in Main relay power circuit and E/R JUNCTION BOX 10A SNSR3 FUSE and go to "Verification of Vehicle Repair".
Check Lambda sensor heater control circuit voltage
IG KEY "OFF", ENGINE "OFF".
Disconnect Lambda sensor connector.
IG KEY "ON".
Measure the voltage of Lambda sensor connector terminal 5.
Specification : 2.0V~2.5V
Is the measured voltage within the specification?
▶ Go to "Component Inspection".
▶ No voltage is detected : Go to "2. Check open in Lambda sensor heater control circuit" as follows.
▶ High voltage is detected : Repair short to battery in control circuit and go to "Verification of Vehicle Repair".
Check open in Lambda sensor heater control circuit
IG KEY "OFF", ENGINE "OFF".
Disconnect Lambda sensor connector and ECM connector.
Check continuity between Lambda sensor connector terminal 5 and ECM connector (C244-K) terminal 51.
Specification : Continuity (below 1.0Ω )
Is the measured resistance within the specification?
▶ Repair short to ground in control circuit and go to "Verification of Vehicle Repair".
▶ Repair open in Lambda sensor heater control circuit and go to "Verification of Vehicle Repair".
Check Lambda sensor component heater coil resistance
IG KEY "OFF", ENGINE "OFF".
Disconnect Lambda sensor connector.
Check continuity between Lambda sensor component connector 2 and 5.
Specification : approx. 4.8Ω at room temperature
Is the measured resistance within the specification?
▶ Go to "Verification of Vehicle Repair".
▶ Replace Lambda sensor and go to "Verification of Vehicle Repair".
After a repair, it is essential to verify that the fault is corrected.
After connecting Scantool select "DIAGNOSTIC TROUBLE CODES(DTCs)" mode.
Clear recorded DTC using Scantool.
Drive the vehicle within DTC "Enable conditions" in "General information".
After selecting "DIAGNOSTIC TROUBLE CODES(DTCs)" mode and check if DTC is recorded again.
Are any DTCs recorded ?
▶ Go to the DTC guide of recorded NO. in Scantool.
▶ System operates within specification.
