RING-BACKUP 5071222 - Caterpillar

Illustration 1 g03315558
Circuit of the right track speed sensor
Right Speed SensorThis diagnostic code is recorded when the electronic control module (ECM) reads the Right speed sensor signal as having an abnormal frequency.Note: The engine must be running and the lever must be in FORWARD position or the REVERSE position in order for this diagnostic code to be detected. The possible causes of this diagnostic code are the following faults:
The fuse has failed.
The +V circuit from the ECM to the sensor is open.
The return circuit is open.
The signal circuit is open or the sensor is disconnected.
The signal circuit is shorted to +V.
The signal circuit is shorted to ground.
The sensor is misaligned or adjusted incorrectly.
The sensor is malfunctioning.
The ECM has failed. This is unlikely.Certain operating procedures can cause this diagnostic code to appear when the speed sensor is operating properly. Stall conditions can trigger these diagnostic codes. For example, this diagnostic code is generated under the following conditions:
The machine is pushed against a truck for more than seven seconds, but the machine did not move.
The machine is propelled against the parking brake for more than seven seconds.If any of these events is the cause, the diagnostic code should become inactive once the machine is moving for a few seconds. In these cases, the sensor is working properly. The following procedures do not need to be performed.System Response:The results of this diagnostic code are the following:
The diagnostic lamp for the propel function in the operator station will be ON.
The lever in any one of the following positions will not cause the propelling of the machine: NEUTRAL position, FORWARD and REVERSE position.
The machine will start propelling in the open loop when the problem has been fixed and another neutral reset is performed.Note: The diagnostic code for the diagnostic code will be logged, but not active. If a speed sensor signal comes back for five seconds in the open loop, the diagnostic code lamp will turn off, but the machine will remain in the open loop until another neutral reset is performed.Note: Ensure that the diagnostic code CID 031 FMI F08 for the sensor is on hold. Also check whether the diagnostic code indicator that is in the ECM display is on. This procedure can cause new diagnostic codes to be recorded. Ignore these created codes. When the procedure is completed, clear the created codes.Test Step 1. Check Return Circuit
Turn the key start switch to the OFF position.
Disconnect the machine harness connector from the sensor.
At the machine harness connector for the sensor, measure the resistance between return contact B (wire P202-BR(Brown)) and the frame ground. Expected Result:The resistance should measure 5 ohms or less.Results:
OK - The resistance measures 5 ohms or less. The return circuit is correct. Proceed to Test Step 2.
NOT OK - The resistance measurement is greater than 5 ohms. Repair: The return circuit is open. Wire P202-BR(Brown) is open between the sensor contact B and the contact 39 of the ECM. Repair the wiring harness or replace the wiring harness.STOPTest Step