DTC Code | DTC Name |
---|---|
P0544 | Exhaust GAS Temperature Sensor Circuit (Bank 1 Sensor 1) |
P0545 | Exhaust Gas Temperature Sensor Circuit Low (Bank 1 Sensor 1) |
P0546 | Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 1) |
DESCRIPTION
The exhaust gas temperature sensors are installed in front of and behind the DPF (*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 becomes, the greater the thermistor resistance value becomes. The exhaust gas temperature becomes, the lower the thermistor resistance value becomes.
The higher 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 (bank 1 sensor 1) and THCO (bank 1 sensor 2) 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 (bank 1 sensor 1) and THCO (bank 1 sensor 2) also changes. Based on these signals, when DPF catalyst regeneration is needed, the ECM operates the injector to obtain target upstream temperature of the DPF catalytic converter as monitored through sensor 1. In addition, the ECM monitors the rate of DPF catalytic converter temperature increase using sensor 2.
*1: Diesel Particulate Filter
DTC No. | DTC Detection Condition | Trouble Area |
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P0544 | Sensor 1 output is less than 0.2 V or more than 4.95 V for 8 seconds or more (1 trip detection logic) |
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P0545 | Sensor 1 output is less than 0.2 V for 8 seconds or more (1 trip detection logic) |
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P0546 | Sensor 1 output is more than 4.95 V for 8 seconds or more (1 trip detection logic) |
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Tech Tips
Sensor 1 represents a sensor located upstream on the DPF catalytic converter.
Sensor 2 represents a sensor located downstream on the DPF catalytic converter.
After confirming DTC P0544, P0545, P0546, P2031, P2032, and P2033, check the upstream and downstream exhaust gas temperature by selecting the following menus on the tester: Powertrain / Engine and ECT / Exhaust Temp (In) and Exhaust Temp (Out).
Result | ||||||||||
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WIRING DIAGRAM
INSPECTION PROCEDURE
Note
After replacing the ECM, the new ECM needs registration Click here and initialization Click here.
PROCEDURE
READ VALUE USING INTELLIGENT TESTER (EXHAUST GAS TEMPERATURE)
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menu items: Powertrain / Engine and ECT / Exhaust Temp (In) and Exhaust Temp (Out). Read its value displayed on the intelligent tester.
Standard |
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Same as the actual exhaust gas temperature (50 to 700°C [122 to 1292°F] during idling after warm-up), and varies after an engine speed of 3000 rpm is maintained for 1 minute. |
Result | ||||||||
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Tech Tips
If there is a short circuit, the intelligent tester will indicate 0°C (32°F).
If there is an open circuit, the intelligent tester will indicate 1000°C (1832°F).
B |
READ VALUE USING INTELLIGENT TESTER (SHORT IN WIRE HARNESS) Click here |
C |
CHECK FOR INTERMITTENT PROBLEMS |
A |
READ VALUE USING INTELLIGENT TESTER (OPEN IN WIRE HARNESS)
Disconnect the exhaust gas temperature sensor connector.
Connect terminals 1 and 2 of the exhaust gas temperature sensor wire harness side connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menu items: Powertrain / Engine and ECT / Exhaust Temp (In).
Read the value.
Standard |
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0°C (32°F) |
Reconnect the exhaust gas temperature sensor connector.
NG |
READ VALUE USING INTELLIGENT TESTER (OPEN IN ECM) Click here |
OK |
REPLACE EXHAUST GAS TEMPERATURE SENSOR
READ VALUE USING INTELLIGENT TESTER (OPEN IN ECM)
Disconnect the exhaust gas temperature sensor connector.
Connect terminals THCI and E2 of the ECM connectors.
Tech Tips
Before checking, do a visual and contact pressure check on the ECM connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menu items: Powertrain / Engine and ECT / Initial Exhaust Temp (In).
Read the value.
Standard |
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0°C (32°F) |
Reconnect the exhaust gas temperature sensor connector.
NG |
REPLACE ECM |
OK |
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - EXHAUST GAS TEMPERATURE SENSOR)
READ VALUE USING INTELLIGENT TESTER (SHORT IN WIRE HARNESS)
Disconnect the exhaust gas temperature sensor connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menu items: Powertrain / Engine and ECT / Exhaust Temp (In).
Read the value.
Standard |
---|
1000°C (1832°F) |
Reconnect the exhaust gas temperature sensor connector.
NG |
READ VALUE USING INTELLIGENT TESTER (SHORT IN ECM) Click here |
OK |
READ VALUE USING INTELLIGENT TESTER (SHORT IN ECM)
Disconnect the exhaust gas temperature sensor connector.
Disconnect the ECM connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menu items: Powertrain / Engine and ECT / Exhaust Temp (In).
Read the value.
Standard |
---|
1000°C (1832°F) |
Reconnect the exhaust gas temperature sensor connector.
Reconnect the ECM connector.
NG |
REPLACE ECM |
OK |
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - EXHAUST GAS TEMPERATURE SENSOR)