Description & Operation: Gauges: Odometer

NOTE: If a condition exists in which a valid odometer memory value cannot be read from the NVM, the word "Error" will be displayed.

The digital odometer displays either miles or kilometers depending on the selection made with the ENG/MET button. The total odometer display consists of six digits. Accumulated mileage is stored in a Non-Volatile Memory (NVM) every 1.0 mile (1.6 km). The total odometer mileage and the mileage of the two trip odometers are stored in the NVM in miles. The total odometer range is from 000000 to 925691 miles, and both the metric and English displays will stop once this value is attained. See Figure .

The following are several areas of concern that may affect speedometer and odometer readings: Tires, Final Drive Ratio, and The Speedometer Drive Gear and/or Speedometer Gear.

Improper tire rolling radius, inflation pressure, temperature, and size may contribute to inaccurate system readings. Perform system accuracy testing after the tires are set to the correct pressure and after the tires are warmed for a short period. Driving at a constant speed within the posted speed limit on smooth, dry pavement will obtain the best results. The final drive ratio of the transaxle must be known to select or to check if the proper speedometer drive gear and speedometer gears are present. The speedometer drive gear is located inside the transaxle and is not easily accessed for change. The speedometer gear rotates the Vehicle Speed Sensor (VSS).

The maximum allowable odometer system accuracy error is +/- 3.75 percent of the actual distance traveled. Lincoln-Mercury motor vehicles are well within these limits. As a general rule, the indicated speed is equal to or greater than the actual speed. This is intended to protect the consumer from violating speed laws. Most consumer concerns are related to speedometers reading too high at true speeds between 50-65 mph (80-105 km/h). In this speed range, the worst case errors may indicate a speed that is 10 percent greater than the true speed.

The integrated converter circuit processes information sent to it by the VSS. If the system components send the wrong number of revolutions per kilometer/mile to the speedometer, the speedometer and the odometer will display an inaccurate speed reading and amount of distance traveled. If the customer concern indicates a speed accuracy problem, first check the accuracy of the odometer. Odometer accuracy can be checked by using roads established at mile increments or a known local course.

If roads with mile markers are used, a five mile stretch is recommended to allow for inaccuracies. If an error is greater than 3.75 percent, a change in the VSS drive/driven gear ratio, tire size, or tire inflation may be needed. Check the odometer again to verify any corrective action. If the indicated speed error exceeds 10 percent between 50-60 mph (80-96 km/h), replace the Electronic Instrument Cluster (EIC).

Federal law requires that any replacement odometer must register the same mileage as that on the removed odometer. Service replacement EIC with the mileage preset to actual vehicle mileage are available through Ford Electronic Service Centers. In nearly all instances, the mileage continues to accumulate in the odometer memory even if the odometer does not display mileage. This mileage can usually be verified by the Electronic Service Centers. Contact the Electronic Service Center for instructions to receive a replacement EIC with the mileage preset to actual mileage. If the actual vehicle mileage cannot be verified, the Electronic Service Center will supply an EIC with the odometer display preset to zero (0) miles. An odometer mileage sticker is supplied with the replacement EIC. This sticker must display the estimated vehicle mileage and is to be affixed to the left hand front door.