Lexus IS250 IS220d GSE20 ALE20 2AD-FHV ENGINE CONTROL SYSTEM
READ VALUE OF EXHAUST GAS TEMPERATURE SENSOR
CHECK EXHAUST GAS TEMPERATURE SENSOR (OPEN IN SENSOR)
CHECK HARNESS AND CONNECTOR (EXHAUST GAS TEMPERATURE SENSOR - ECM)
CHECK EXHAUST GAS TEMPERATURE SENSOR (SHORT IN SENSOR)
CHECK HARNESS AND CONNECTOR (EXHAUST GAS TEMPERATURE SENSOR - ECM)
DTC P0544 Exhaust GAS Temperature Sensor Circuit (Bank 1 Sensor 1)
DTC P0545 Exhaust Gas Temperature Sensor Circuit Low (Bank 1 Sensor 1)
DTC P0546 Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 1)
DTC P2031 Exhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 2)
DTC P2032 Exhaust Gas Temperature Sensor Circuit Low (Bank 1 Sensor 2)
DTC P2033 Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 2)
DESCRIPTION
The exhaust gas temperature sensors are installed before and after the DPNR (*1) catalytic converter to sense the exhaust gas temperature.
A thermistor built into the sensor changes its resistance value according to the exhaust gas temperature. The lower the exhaust gas temperature, the greater the thermistor resistance value. The higher the exhaust gas temperature, the lower the thermistor resistance value.
The exhaust gas temperature sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the exhaust gas temperature sensor from terminals THCI (upstream) and THCO (downstream) via resistor R.
The resistor R and the exhaust gas temperature sensor are connected in series. When the resistance value of the exhaust gas temperature sensor changes in accordance with changes in the exhaust gas temperature, the voltage at terminals THCI (upstream) and THCO (downstream) also changes. Based on these signals, when DPNR catalyst regeneration is needed, the ECM operates the exhaust fuel addition injector to obtain target upstream temperature of the DPNR catalytic converter as mentioned through sensor 1. In addition, the ECM monitors the rate of DPNR catalytic converter temperature increase using sensor 2.
*1: Diesel Particulate-NOx Reduction system.
| DTC No. | DTC Detection Condition | Trouble Area |
| P0544 | Sensor 1 output is less than 0.2 V or more than 4.95 V for 3 seconds or more (1 trip detection logic) | Open or short in exhaust gas temperature sensor (upstream) circuit Exhaust gas temperature sensor (upstream) ECM |
| P0545 | Sensor 1 output is less than 0.2 V for 3 seconds or more (1 trip detection logic) | |
| P0546 | Sensor 1 output is more than 4.95 V for 3 seconds or more (1 trip detection logic) | |
| P2031 | Sensor 2 output is less than 0.2 V or more than 4.95 V for 3 seconds or more (1 trip detection logic) | Open or short in exhaust gas temperature sensor (downstream) circuit Exhaust gas temperature sensor (downstream) ECM |
| P2032 | Sensor 2 output is less than 0.2 V for 3 seconds or more (1 trip detection logic) | |
| P2033 | Sensor 2 output is more than 4.95 V for 3 seconds or more (1 trip detection logic) |
- HINT:
| Condition | Exhaust Gas Temperature | Exhaust Gas Temperature Sensor Condition |
| Idling after warm-up | Constant at 50 to 700°C (122 to 1,292°F) | Normal |
| 0°C (32°F) | Short circuit | |
| 1,000°C (1,832°F) | Open circuit |
MONITOR DESCRIPTION
The ECM constantly monitors the output voltages from the sensors in order to detect problems with the sensors. When the sensor output voltage deviates from the normal operating range (between 0.2 V and 4.95 V) for more than 3 seconds after the engine is warmed up, the ECM interprets this as a malfunction of the sensor circuit, and illuminates the MIL.
WIRING DIAGRAM
INSPECTION PROCEDURE
- NOTICE:
- After replacing the ECM, the new ECM needs registration and initialization .
| 1.READ VALUE OF EXHAUST GAS TEMPERATURE SENSOR |
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Enter the following menus: "Powertrain / Engine / Initial Exhaust Temp (IN) and Initial Exhaust Temp (OUT)" and read its value displayed on the intelligent tester.
- Standard:
- Same as the actual exhaust gas temperature (50 to 700°C [122 to 1,292°F] during idling after warm-up), and varies after an engine speed of 3,000 rpm is maintained for 1 minute.
- Result:
Temperature Displayed Proceed to 1,000°C (1,832°F) A 0°C (32°F) (After warming up the engine) B OK: Same as the actual exhaust gas temperature (50 to 700°C [122 to 1,292°F] during idling after warm-up), and varies after maintaining the engine speed of 3,000 rpm for 1 minute after accelerating the engine from idling to 3,000 rpm C
- HINT:
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| A | |
| 2.CHECK EXHAUST GAS TEMPERATURE SENSOR (OPEN IN SENSOR) |
Disconnect the E72*1 or E73*2 exhaust gas temperature sensor connector.
*1: Upstream sensor
*2: Downstream sensor
Connect terminals 1 and 2 of the exhaust gas temperature sensor wire harness side connector.
Connect the intelligent tester to the DLC 3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Enter the following menus: "Powertrain / Engine / Initial Exhaust Temp (IN) and Initial Exhaust Temp (OUT)" and read its value displayed on the intelligent tester.
- Standard:
- 0°C (32°F)
Reconnect the exhaust gas temperature sensor connector.
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| NG | |
| 3.CHECK HARNESS AND CONNECTOR (EXHAUST GAS TEMPERATURE SENSOR - ECM) |
Disconnect the E72*1 or E73*2 exhaust gas temperature sensor connector.
*1: Upstream sensor
*2: Downstream sensor
Disconnect the E59 ECM connector.
Check the resistance.
- Standard resistance:
Tester Connections Specified Conditions THCI (E73-2) - THCI (E59-122) Below 1 Ω THCO (E72-2) - THCO (E59-121) Below 1 Ω ETCI (E73-1) - ETCI (E59-99) Below 1 Ω ETCO (E72-1) - ETCO (E59-98) Below 1 Ω
Reconnect the ECT sensor connector.
Reconnect the ECM connector
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| OK | ||
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| 4.CHECK EXHAUST GAS TEMPERATURE SENSOR (SHORT IN SENSOR) |
Disconnect the E72*1 or E73*2 exhaust gas temperature sensor connector.
*1: Upstream sensor
*2: Downstream sensor
Connect the intelligent tester to the DLC3.
Turn the engine switch ON (IG) and turn the intelligent tester ON.
Enter the following menus: "Powertrain / Engine / Initial Exhaust Temp (IN) and Initial Exhaust Temp (OUT)" and read its value displayed on the intelligent tester.
- Standard:
- 1,000°C (1,832°F)
Reconnect the exhaust gas temperature sensor connector.
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| NG | |
| 5.CHECK HARNESS AND CONNECTOR (EXHAUST GAS TEMPERATURE SENSOR - ECM) |
Disconnect the E72*1 or E73*2 exhaust gas temperature sensor connector.
*1: Upstream sensor
*2: Downstream sensor
Disconnect the E59 ECM connector.
Check the resistance.
- Standard resistance:
Tester Connections Specified Conditions THCI (E73-2) or THCI (E59-122) - Body ground 10 kΩ or higher THCO (E72-2) or THCO (E59-121) - Body ground 10 kΩ or higher
Reconnect the ECT sensor connector.
Reconnect the ECM connector.
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| OK | ||
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