CONDENSER & MTG GP-REFRIGERANT 2620942 - Caterpillar

Illustration 1 g02743418
Connections of the Transmission Hydrstatic Loop "A" Pressure SensorThis diagnostic code is related to the transmission hydrostatic loop "A" pressure sensor. An FMI 04 means the Transmission ECM has determined the voltage of the sensor output signal is below normal.The sensor output is a Pulse Width Modulated (PWM) frequency signal at 500Hz ( 100Hz). The signal duty cycle changes as the sensor pressure changes.
Illustration 2 g02739817
Bulkhead Connectors (1) Loop B Sensor (2) Flushing Oil Temp Sensor (3 ) Loop A SensorThis sensor is internal to the transmission. The sensor is part of the sensor/pigtail/bulkhead assembly (3). There are external bulkhead connectors at the transmission case as shown in Illustration 2.This troubleshooting procedure is initially conducted at the external bulkhead connector on the transmission. The bulkhead connector stays in the plate and is held in place via a snap ringThe bulkhead is one end of the pigtail that connects to the sensor. The pigtail is potted to the pressure sensor and cannot be detached without damaging the sensor.Possible causes for this diagnostic code are:
The sensor has failed.
The ECM pin is shorted to ground.
The transmission ECM has failed, but is unlikely.This code would not be shown if there is an existing 8V supply diagnostic code.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 2838 FMI 04 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 external bulkhead connector for the Loop A Pressure Sensor (3), insert the multimeter probes at contact 1 (J850-WH), the sensor power supply, and contact 2 (J764-BR), the sensor GROUND.
Measure the voltage from contact 1 to contact 2.Expected Result:The voltage measured is 8 0.5 VDC.Results:
YES - The voltage measured is 8 0.5 VDC. The power supply is correct. Go to Test Step 2.
NO - The voltage measurement is less than 8 0.5 VDC. The voltage is not correct. There is an open, or loose, connection in the circuit.Repair: Repair, or replace, the machine harness as needed. There is a problem in the power supply circuit in the machine harness.Poor connections are often the cause of a problem in electrical circuits. Inspect the harness connectors involved in the circuit. Verify that all of the connections in the circuit are clean, secure, and in good condition. To verify that the problem was corrected, and that the CID 2838 - FMI