C2.4 Tier 4 Final Engines for Caterpillar Built Machines Caterpillar

Sensor Signal (Analog, Passive) - Test

Usage:

Engine Temperature Sensor Open or Short Circuit

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Table 1
Code	Description	Conditions Present	Response
110-3	Coolant Temp Sensor Voltage Above Normal	Battery voltage is normal. Voltage of coolant temperature sensor is 4.870 V or above for 3 seconds or more.	Duringstart-up the system will default to −25° C (−13° F) and under other conditions it will be 80° C (176° F). Engine derates 25% EGR stops Intake throttle fully open. Warning Level 2 White smoke increases at low temperature
110-4	Coolant Temp Sensor Voltage Below Normal	Battery voltage is normal. Voltage of coolant temperature sensor is 0.176 V or less for 3 seconds or more.
171-3	Intake Air Temp Sensor (in MAF) Voltage Above Normal	Battery voltage is normal. Intake air temperature built-in MAF sensor voltage is 4.850 V or more for 3 seconds or more.	The system will use a default of 25° C (77° F). Warning Level 2
171-4	Intake Air Temp Sensor (in MAF) Voltage Below Normal	Battery voltage is normal. Intake air temperature built-in MAF sensor voltage is 0.2 V or less for 3 seconds or more.
172-3	Intake Air Temp Sensor Voltage Above Normal (in Boost Pressure Sensor, Turbocharged versions only)	Battery voltage is normal. Voltage of intake air temperature sensor is 4.95 V or above for 3 seconds or more.	The system will use a default of 40° C (104° F). Warning Level 2 White smoke increases at low temperature.
172-4	Intake Air Temp Sensor Voltage Below Normal (in Boost Pressure Sensor, Turbocharged versions only)	Battery voltage is normal. Voltage of intake air temperature sensor is 0.2 V or less for 3 seconds or more.
3242-3	DPF Inlet Temperature Sensor Voltage Above Normal	Battery voltage is normal. Coolant temperature is 50° C (122° F) or more continues longer than 10 minutes after engine starting. T0 is between 100° C (212° F) and 800° C (1472° F) continues longer than 10 seconds or T2 is between 100° C (212° F) and 800° C (1472° F) continues longer than 10 seconds. DPF inlet temperature sensor (T1) voltage is 4.92 V or more for 2 minutes or more.	The system will use a default of 0° C (32° F). Engine derates 25% Warning Level 2
3242-4	DPF Inlet Temperature Sensor Voltage Below Normal	Battery voltage is normal. Temperature sensor voltage is 0.08 V or less for 5 seconds or more.
3246-3	DPF Outlet Temperature Sensor Voltage Below Normal	Open circuit or +B short circuit of sensor/harness. Battery voltage is normal. Coolant temperature is 50° C (122° F) or more continues longer than 10 minutes after engine starting. T0 is between 100° C (212° F) and 800° C (1472° F) and continues longer than 10 seconds or T1 is between 100° C (212° F) and 800° C (1472° F) and continues longer than 10 seconds. DPF outlet temperature sensor (T2) voltage is 4.92 V or more for 2 minutes or more.
3246-4	DPF Outlet Temperature Sensor Voltage Below Normal	Battery voltage is normal. Temperature sensor voltage is 0.08 V or less for 5 seconds or more.
4765-3	DOC Inlet Exhaust Temp Sensor Voltage Above Normal	Coolant temperature is 50° C (122° F) or more continues longer than 5 minutes after engine starting. T1 is between 100° C (212° F) and 800° C (1472° F) continues longer than 10 seconds or T2 is between 100° C (212° F) and 800° C (1472° F) continues longer than 10 seconds. DOC inlet temperature sensor (T0) voltage is 4.92 V or more for 2 minutes or more.
4765-4	DOC Inlet Temperature Sensor Voltage Below Normal	Battery voltage is normal. Temperature sensor voltage is 0.08 V or less for 5 seconds or more.

Note: A -3 code is detecting an open circuit or +B short circuit of the sensor or the wiring harness.

Note: A -4 code is detecting a ground short circuit of the sensor or the wiring harness.

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Illustration 1	g06111700
Mass air flow sensor (temperature sensor built in)

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Illustration 2	g06111708
Boost pressure sensor (temperature sensor built in) - Turbocharged versions only

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Illustration 3	g06111715
DOC inlet temperature sensor (T0)

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Illustration 4	g06111720
DPF inlet temperature sensor (T1)

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Illustration 5	g06111723
DPF outlet temperature sensor (T2)

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Illustration 6	g06111727
Coolant temperature sensor

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Table 2
Resistance of Temperature Sensors at Specific Temperatures
Temperature	Coolant, Air Inlet (in Mass Air Flow sensor)	Air Inlet Temperature Sensor (Turbocharged versions only)
20° C (68° F)	Approximately 2.4 Ω	Approximately 2.4 Ω
40° C (104° F)	Approximately 1.2 Ω	-
60° C (140° F)	Approximately 0.58 Ω	Approximately 0.58 Ω
80° C (176° F)	Approximately 0.3 Ω	Approximately 0.18 Ω
100° C (212° F)	Approximately 0.3 v (only applicable to Coolant Temperature Sensor)	-
Resistance of Aftertreatment Temperature Sensor at Specific Temperatures
Temperature	Resistance
100° C (212° F)	Approximately 18.3 Ω
150° C (302° F)	Approximately 7.88 Ω
200° C (392° F)	Approximately 4.00 Ω
250° C (482° F)	Approximately 2.30 Ω

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Table 3
Sensor Signal Voltage at Specified Temperatures in Cat ET
Temperature Displayed in Cat ET	Coolant and Air Inlet Temp (in Boost Press, Turbocharged versions only)	Air Inlet (In Mass Air Flow Sensor)
20° C (68° F)	Approximately 2.4 v	Approximately 3.1 v
40° C (104° F)	Approximately 1.5 v	Approximately 2.2 v
60° C (140° F)	Approximately 0.9 v	Approximately 1.4 v
80° C (176° F)	Approximately 0.5 v	Approximately 0.9 v
100° C (212° F)	Approximately 0.3 v ( 100° C (212° F) (only applicable to Coolant Temp Sensor)	-
Sensor Signal Voltage at Specified Temperatures in Cat ET
Temperature Displayed in Cat ET	Aftertreatment Sensors
100° C (212° F)	Approximately 4.4 v
150° C (302° F)	Approximately 3.7 v
200° C (392° F)	Approximately 3.0 v
250° C (482° F)	Approximately 2.3 v

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Table 4
Troubleshooting Test Steps	Values	Results
1. Check Resistance of the Temperature Sensor Between Signal and Ground Refer to the tables above for resistance specifications. A. For the temperature sensors built into the boost Pressure sensor (turbocharged versions only) or Mass Air Flow sensor refer to circuit diagram.	Resistance	Result: The resistance measurement is not within the specification. Replace the temperature sensor. Result: The resistance of the temperature sensor is within specification. Proceed to Test Step 2.
2. Check Resistance At the ECM Connector Terminals A. Refer to the circuit diagrams B. Check voltages in Cat ET.	Harness	Result: If not good then the fault is in the wiring harness, the connectors to the ECM are not fully seated, or the ECM or sensor pins are bent. Repair or replace. Result: If good, then recheck to see if the fault code is still active. Proceed to Test Step 3.
3. Electrical Connectors A. Refer to Electrical Connectors - Inspect	Connectors	Result: The electrical connections are not OK. There is still a problem in the harness or connectors. Make the necessary repairs. Result: The electrical connections are OK. STOP

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).

Exhaust Gas Temperature Sensors

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Table 5
Diagnostic Trouble Codes
Code	Description	Conditions Present	Response
523599-0	All Exhaust Gas Temperature Sensor Failure	All exhaust temperature sensor failure simultaneously. Engine speed is 1400 rpm or more. Quantity of injection is 30 mm3/st or more. Coolant temp is 50° C (122° F) or more and continues longer than 5 minutes. Passed 100 seconds after cranking. All exhaust temperature sensor failure (sensor low) simultaneously for 100 seconds or more.	Engine derates 25% Warning Level 2

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Table 6
Troubleshooting Test Steps	Values	Results
1. Other Active or Logged Diagnostic Codes A. Check for other active or logged diagnostic codes, which can help determine the cause of this diagnostic code.	Codes	Result: Other active or logged diagnostic codes are not present. Proceed to Test Step 2.
2. Inspect Electrical Connectors and Wiring A. Check that the connector is fully seated at the sensor. B. Check that the wires to the connector are not pulled tight at the connector, not rubbing, not broken. C. Check that the connector pins and sockets are not damaged and aligned correctly. D. Check the harness for corrosion, abrasion, and pinch points from the sensor to the Engine ECM.	Loose connections, poor routings, damaged wires	Result:There is a fault in a connector or wiring. Replace the engine harness. Result: The harness is OK. Proceed to Test Step 3.
3. Temperature Sensors A. Check the three temperature sensors resistance and voltage of circuit.	Voltage and Resistance	Result: The values for the sensors are not within specification. Result: The values for the sensors are within specification. Proceed to Test Step 4.
4. Exhaust Temperature Sensor Installation A. Check for correct installation of the three exhaust gas temperature sensors on the aftertreatment.	Sensor	Result: The exhaust temperature sensors are not installed correctly. Make the necessary repairs. Result: The exhaust temperature sensors are installed correctly. STOP

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).