RING-TORIC 3144133 - Caterpillar

Illustration 1 g02065914
Schematic of the Boom Up Pilot Pressure sensor
This diagnostic code is associated with the Boom Up Pilot Pressure sensor. An FMI 03 diagnostic code means the Machine ECM has determined the signal output voltage of the sensor is above normal.Possible causes for this diagnostic code are:
The sensor power supply may have failed.
The sensor may have failed.
The sensor output signal may be shorted to a voltage source.
The sensor output signal may be open.
The machine ECM may have failed. A failure of the ECM is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes now, but clear those codes after the original diagnostic code has been corrected. Note: Poor connections are often the cause of a problem in electrical circuits. Before performing this procedure, inspect all of the harness connectors involved in the circuit. Verify that all of the connections in the circuit are clean, secure, and in good condition. If a problem is found with any of the connections: correct the problem and verify that diagnostic code CID 2429 FMI 03 is still active, before performing the following procedures. Test Step 1. VERIFY THE +8 VDC SUPPLY.
Turn the key start switch and the disconnect switch to the ON position. Do NOT start the engine.
Do NOT disconnect any of the machine harness connectors at this time.
At the back of the harness connector for the Boom Up Pilot Pressure sensor, insert 7X-1710 Multimeter Probes along the sensor voltage supply, contact A (J850-PU(Purple)), and the sensor Analog Return, contact B (235-BK(Black)).
Measure a DC voltage from contact A to contact B. Expected Result:The voltage measurement is 8 0.5 VDC.Results:
YES - The measurement is 8 0.5 VDC. The power supply is correct. Go to Test Step 2.
NO - The voltage is NOT 5 VDC. The 5 VDC power supply in the machine ECM has failed, or the machine harness has failed. Go to Test Step 3Test Step 2. CHECK THE SENSOR, THE ECM, AND THE CIRCUIT CONNECTIONS IN THE MACHINE HARNESS.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the Boom Up Pilot Pressure sensor.
At the Boom Up Pilot Pressure sensor, place a jumper wire between the pin for contact 3 (M843-PU(Purple) ) and the pin for contact 2 (235-BK(Black)) on the sensor harness connector.
Turn the key start switch and the disconnect switch to the ON position. Do NOT start the engine.
Observe the status of the diagnostic code. Expected Result:The CID 2429 FMI 03 diagnostic code does not change. Results:
YES - The diagnostic code does not change, and remains active. The sensor is NOT the cause of the problem. The machine harness may have failed, or the ECM may have failed. Go to Test Step 3.
NO - The CID 2429 FMI 03 diagnostic code is no longer active. The code has changed into either an active CID 2429 FMI 04 diagnostic code, an active CID 2429 FMI 06 diagnostic code, or both. The ECM has