VALVE GP-RELIEF 1350814 - Caterpillar

Illustration 1 g02711849
Connections of the Transmission Synchronizer # 1 Position SensorThis diagnostic code is associated with the transmission synchronizer # 1 position sensor. The FMI 08 means that the ECM has determined that that the signal frequency or the signal pulse width is not within the expected range.The sensor is an analog PWM sensor that has an operating duty cycle of 10% at minimum sensed position to 90% at maximum sensed position. The sensor is used to read the position of the synchronizer #1 fork of the transmission. The position of the synchronizer defines whether the synchronizer is neutralized or somewhere in-between.Sensor output, versus synchronizer position, is dependent on a particular transmission design.The possible causes of this diagnostic code are listed below:
Missing 8V supply and/or ground
Intermittent connections, or poor connections
The sensor has failed
Mechanical devices are loose
The Transmission ECM has failed. This condition is unlikelyThis 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 and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the CID 2817 FMI 08 diagnostic code is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. CHECK THE VOLTAGE AT THE SENSOR
Do not disconnect the harness connector from the sensor.
At the back of the harness connector for the sensor, insert a multimeter probe along contact 1 J850-WH.
Turn the key start switch and the disconnect switch to the ON position.
At the machine harness connector for the sensor, measure the voltage between contact 1 (wire J850-WH) and contact 2 (wire F764-BR).Expected Result:The voltage is 8 0.5 VDC.Results:
OK - The voltage is 8 0.5 VDC. Proceed to Test Step 3.
NOT OK - The voltage is NOT 8 0.5 VDC. The circuit is open.Repair: Repair or replace the machine harness.STOPTest Step 2. CHECK SIGNAL CIRCUIT FOR AN OPEN
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connectors and the ECM harness connectors from the sensor and the ECM.
At the sensor connector, connect a jumper wire from the signal wire X954-PU to a known ground.
At the ECM connector, measure the resistance between the signal wire X954-PU and a known ground.Expected Result:The resistance is less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. Proceed to Test Step 3.
NOT OK - The resistance is greater