understanding the odo diff report
Vehicle Odometer Difference Report
A diagnostic report used to examine the differences between the LTD odometer and an actual input odometer/last good reading (JX55 or keypad entry). The LTD Odometer is exported to EAM systems to schedule bus maintenance. The LTD Odometer will increment based on accurate historical data calculations, when necessary, allowing time for problems to be corrected with input odometers.
1) If there is a difference between the LTD/On-board and Last Good Reading, proceed to the Vehicle section in Data Tools.
2) Go to the Service History for the vehicle to check for problems with the Actual Input Odometer such as:
a. Stuck odometer: odometer no longer incrementing.
i. If the Vehicle Odometer source is J and Actual Input Odometer is 0.0, check the JX-55 configuration for proper setting (17 for J1939 and 0 for J1708), or check the bus ECM and J1939 system for issues.
ii. If Vehicle Odometer source is J and the Actual Input Odometer is the same whole number for each transaction, example 50,500, check the configuration value, and check the ECM odometer with a diagnostic laptop. Ensure correct pin-outs at the bus connection for the JX55.
b. Offline module (Unit No Longer Responds to Queries): if the Vehicle Source is blank and the odometer is 0.0, the unit is offline. Ensure the JX55 is still connected to bus connector. Ensure connector has power from the bus. Replace JX with new one if necessary.
c. Diagnostic Module Hardware Problem: the JX55 is not working properly and needs to be replaced.
d. Unit Appears To Count Low Mileage: 4 of the last 10 transactions show Lower MPG bound exceptions, lower than expected transaction MPG. If there are only a few this could indicate an anomaly. If this occurs repeatedly, check the ECM tire factor setting for proper mileage increments.
Report Column Header Key
• Vehicle Number: 6-digit vehicle number.
• Vehicle Type: Used for organizing reports, vehicles can be assigned a vehicle type.
• Last Service Date: Date of last transaction.
• Device Status: Describes any reported problem with module. See key below.
• Avg MPG: LTD MPG at last transaction. The LTD MPG is an average of last 5 reasonable transaction MPGs.
• Life-to-Date Odometer: This is the FW protected, or LTD, odometer exported to Maximo.
• Expected Odometer Reading: This is a tracking odometer used to keep the LTD odometer incrementing in case of a problem with the Input Odometer.
• Last Good Odometer Reading: This is the last good reading from the module.
• Diff w/ Last Good Odometer Reading
LTD: the difference between last good JX reading and the LTD odometer for Maximo.
On-board: the difference between last good JX reading and the onboard tracking odo.