SPACER 8H0908 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with the sensor. Also use this procedure if any one of the diagnostic codes in Table 1.
Table 1
Diagnostic Codes Table
CDL Code and Description Comments
110-3
Engine Coolant Temperature Sensor : Voltage Above Normal The code is logged if the engine has been running for more than 7 minutes and an open circuit has been detected.
110-4
Engine Coolant Temperature Sensor : Voltage Below Normal The code is logged. The ECM detects voltage that is not in the acceptable range.
172–3
Intake Manifold Air Temperature Sensor : Voltage Above Normal The code is logged.
The ECM detects voltage that is not in the acceptable range.
172-4
Intake Manifold Air Temperature Sensor : Voltage Below Normal The code is logged.
The ECM detects voltage that is not in the acceptable range.
174-3
Fuel Temperature Sensor : Voltage Above Normal The code is logged. The ECM will flag the fuel temperature as invalid data and the fuel temperature is set to a default value of 40 °C (104 °F).
174-4
Fuel Temperature Sensor : Voltage Below Normal The code is logged. The ECM will flag the fuel temperature as invalid data and the fuel temperature is set to a default value of 40 °C (104 °F).
3683-3
Auxiliary Temperature #2 : Voltage Above Normal The code is logged.
The ECM detects voltage that is not in the acceptable range.
3683-4
Auxiliary Temperature #2 : Voltage Below Normal The code is logged.
The ECM detects voltage that is not in the acceptable range.
1836-3
Auxiliary Temperature Sensor : Voltage Above Normal The code is logged. The ECM will flag the temperature as invalid data and the temperature is set to a default value.
1836-4
Auxiliary Temperature Sensor : Voltage Below Normal The code is logged. The ECM will flag the temperature as invalid data and the temperature is set to a default value.
3372-3
Engine Charge Air Cooler #1 Outlet Temperature Sensor : Voltage Above Normal The code is logged.
The ECM detects voltage that is not in the acceptable range.
3372-4
Engine Charge Air Cooler #1 Outlet Temperature Sensor : Voltage Below Normal The code is logged.
The ECM detects voltage that is not in the acceptable range.
Illustration 1 g06114590
Schematic for the passive analog sensors
Probable Causes
Codes
Short circuit
Open circuit
Wiring
EGR temperature sensorRecommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect to Cat® Electronic Technician (ET).
B. Turn the keyswitch to ON.
C. Access the "Active Diagnostic Code" screen on Cat ET.
Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
D. Look for -3 and/or -4 codes:
Codes
Result: A -3 diagnostic code is active.
Proceed to Test Step 2.
Result: A -4 diagnostic code is active.
Proceed to Test Step 3.
Result: For a diagnostic code that is logged but not currently active, proceed to Test Step 4.
2. Create a Short at the Sensor Connector
A. Turn the keyswitch to OFF.
B. Disconnect the suspect sensor.
C. Install the jumper wire between terminal 1 (sensor signal) and terminal 2 (sensor return) at the sensor connector.
D. Turn the keyswitch to ON.
E. Monitor the diagnostic codes on Cat ET. Check for an active -4 diagnostic code for