BOLT 7X0295 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the sensors or if any one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
105-3 Inlet Manifold Temperature Sensor voltage above normal The engine's Electronic Control Module (ECM) detects signal voltage that is more than 4.8 VDC for one second.
The ECM has been powered for at least three seconds. The code is logged.
The value of the parameter is set to zero.
105-4 Inlet Manifold Temperature Sensor voltage below normal The ECM detects signal voltage that is less than 0.2 VDC for one second.
The ECM has been powered for at least three seconds.
175-3 Engine Oil Temperature Sensor voltage above normal The ECM detects signal voltage that is more than 4.8 VDC for one second.
The ECM has been powered for at least three seconds. The code is logged.
The value of the parameter is set to zero.
175-4 Engine Oil Temperature Sensor voltage below normal The ECM detects signal voltage that is less than 0.2 VDC for one second.
The ECM has been powered for at least three seconds. System OperationUse this procedure to troubleshoot any suspect problems with the following sensors:
Inlet manifold temperature sensor
Engine oil temperature sensorThe sensor signal for the passive sensors is routed from the ECM to the connector for the right rail. The sensor signal is then routed to terminal 1 of each sensor connector. The sensor return for the passive sensors is routed from the ECM to the connector for the right rail. The sensor return is then routed to terminal 2 of each sensor connector.
Illustration 1 g01242605
Typical schematic
Illustration 2 g01242612
P1 ECM connector
(P1-3) Sensor return (left rail)
(P1-14) "Inlet manifold temperature sensor"
(P1-26) Engine oil temperature sensor
(P1-35) Sensor return (right rail)
Illustration 3 g01163206
Sensor connector
(Terminal 1) Sensor signal
(Terminal 2) Sensor return
Illustration 4 g01234146
Location of ECM connectors
Test Step 1. Check for "Active" or "Logged" Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore power to the ECM.
Monitor the diagnostic codes on Cat ET. Check and record any diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Determine if the problem is active and related to one of the following diagnostic codes:
3
4Expected Result:No diagnostic codes are active at this time.Results:
OK - No diagnostic codes are active at this time.Repair: The problem may be intermittent. If the problem is intermittent refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - An active 3 diagnostic code is present. Proceed to Test Step 2.
Not OK - An active 4 diagnostic code is present. Proceed to Test Step 4.Test Step 2. Check for Battery Voltage on the Signal Wire
Measure the voltage on the harness side of the sensor connector between pin 1 and engine ground for the suspect sensor(s). Expected Result:The signal voltage is less than Battery voltage.Results:
OK - The signal voltage is less than Battery voltage. Proceed to Test Step 3.
Not OK - The signal voltage is equal to Battery voltage.Repair: There is a short