SENSOR-PRESSURE 5296549 - Caterpillar

Illustration 4 g02683998
Terminal locations at the P1 ECM connector for the passive sensors
(P1-26) Engine oil temperature
(P1-61) −Battery
(P1-63) −Battery
(P1-65) −Battery
(P1-67) −Battery
(P1-69) −Battery
Illustration 5 g02684004
Terminal locations at the P2 ECM connector for the passive analog sensors
(P2-84) Intake manifold air temperature
(P2-92) Engine oil temperature
Illustration 6 g01436505
Terminal locations at the connector for the passive analog sensor
(Terminal 1) Sensor signal
(Terminal 2) Analog sensor return Test Step 1. Check for Diagnostic Codes that are Active or Logged
Remove electrical power from the engine.
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the engine. Set the engine control to STOP.
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 a diagnostic code has occurred several times. Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a poor connection. The poor connection can occur between a socket and a pin in a connector or between a wire and a terminal.
Determine if the problem is active and related to one of the following failure modes for the analog passive sensor:
-3 code
-4 code
Remove electrical power from the engine. Expected Result:A diagnostic code is not active.Results:
OK - A diagnostic code is not active.Repair: There may be an intermittent electrical problem in the harness or in a connector. If an intermittent electrical problem is suspected, refer to Testing and Adjusting, "Electrical Connectors - Inspect" for information that is related to troubleshooting these problems.STOP
Active -3 - An active -3 diagnostic code is present. The ECM detects an open in the circuit for the sensor. Proceed to Test Step 2.
Active -4 - An active -4 diagnostic code is present. Proceed to Test Step 4.Test Step 2. Check for Battery Voltage on the Signal Wire
Restore electrical power to the engine. Set the engine control to STOP.
Measure the voltage on the harness side of the sensor connector between pin 1 and engine ground for the suspect sensor.
Remove electrical power from the engine. Expected Result:The signal voltage is less than battery voltage.Results:
OK - The signal voltage is less than battery voltage. The circuit for the signal is not shorted to the +Battery. Proceed to Test Step 3.
Not OK - The signal voltage is equal to battery voltage.Repair: There is a short circuit to the +Battery in the harness. Repair the wiring harness or replace the wiring harness. Verify that the repair has resolved the original problem.STOPTest Step 3. Create a Short Circuit at the Connector for the Suspect Sensor
Disconnect the harness connector for the suspect sensor.
Fabricate a jumper wire that is long enough to create a test circuit across the harness side of the sensor connector. Crimp connector pins to each end of the jumper wire.
Install the jumper wire between terminal 1 (sensor signal) and terminal 2 (sensor return) at the sensor connector.
Restore electrical power to the engine. Set the engine control to STOP.
Access the "Active Diagnostic Code" screen on Cat ET.