COUPLING AS 4235071 - Caterpillar

System OperationUse this procedure to troubleshoot any suspect problems with the following sensors for the primary ECM:
Coolant temperature sensor
Intake manifold air temperature sensor
Engine oil temperature sensor
Illustration 1 g03697594
Illustration 2 g03322492
P1 ECM connector
(P1-3) Common Return
(P1-26) Engine oil temperature
Illustration 3 g03322494
P2 ECM connector
(P2-13) SCAC temperature
(P2-17) Common Return
(P2-30) Common Return
(P2-84) Engine coolant temperature
(P2-95) Intake manifold air temperature
Illustration 4 g01155187
Terminal locations at the connector for the passive analog sensors
(Terminal 1) Sensor signal
(Terminal 2) Sensor return
Table 2
Troubleshooting Test Steps Values Results
1. Check for Active Codes and Logged Codes
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector.
B. Restore the electrical power to the ECM.
C. Monitor