PLATE-CAM 3209769 - Caterpillar

System OverviewThe sensor signal for the passive sensor is routed from the ECM to terminal 1 of each sensor connector. The sensor return for the passive sensors is routed from the ECM to terminal 2 of each sensor connector.Diagnostics on the Caterpillar Electronic Technician (ET)Wiggle Test - The Wiggle Test allows you to monitor the status of the signals from the sensors.For additional information regarding the Wiggle Test, refer to the documentation that accompanies the Cat ET software.
Illustration 1 g02133854
Schematic for the passive sensors
Illustration 2 g01155187
Terminal locations at the connector for the passive analog sensors
(Terminal 1) Sensor signal
(Terminal 2) Analog return
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat ET to the service tool connector.
B. Look for these active codes or logged codes:
-3
-4
Note: The engine must be running for 7 minutes in order for a 110-3 code to become active.
Codes
Result: A diagnostic code is logged.
Proceed to Test Step 4.
Result: A -3 diagnostic code is active.
Proceed to Test Step 2.
Result: A -4 diagnostic code is active.
Proceed to Test Step 3.
2. Create a Short at the Sensor Connector
A. Turn the keyswitch to the OFF position.
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 the ON position.
E. Monitor the diagnostic codes on Cat ET. Check for an active -4 diagnostic code for the suspect sensor.
Note: The engine must be running for 7 minutes in order for a 110-3 code to become active.
F. Turn the keyswitch to the OFF position.
-3, -4 Code
Result: The -3 diagnostic code remains active for the suspect sensor.
Repair: There is an open in the harness. Repair the wiring or replace the harness.
Verify that the problem is resolved.
If the repair does not resolve the problem, proceed to Test Step 3.
Result: A -4 diagnostic code became active after creating the short at the sensor connector.
Repair: The wiring is OK. Replace the sensor.
Verify that the problem is resolved.
If the repair does not resolve the problem, proceed to Test Step 3.
3. Create an Open at the Suspect Sensor Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the sensor connector of the suspect sensor with the active -4 diagnostic code.
C. Turn the keyswitch to the ON position.
D. Monitor the diagnostic codes on Cat ET. Check for an active -3 diagnostic code for the suspect sensor.
Note: The engine must be running for 7 minutes in order for a 110-3 code to become active.
E. Turn the keyswitch to the OFF position.
-3, -4 Code
Result: The -4 diagnostic code remains active for the suspect sensor.
Repair: There is a short in the harness. Repair the wiring or replace the harness.
Verify that the problem is resolved.
If the repair does not resolve the problem, proceed to Test Step 4.
Result: A -3 diagnostic code became active after disconnecting the sensor.
Repair: The wiring is OK. Replace the sensor.
Verify that the problem is resolved.
If the repair does not resolve the problem, proceed to Test Step 4.
4. Perform the Wiggle Test
A. Turn the keyswitch to