Using a speedometer tester

WARNING: This page is about a different car, the 2016 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

When only the front or the rear wheels are driven using a speedometer tester, the DSC HU/CM may determine that the vehicle speed signal is in error and the engine cannot be stopped by the normal operation. If the engine cannot be stopped, perform an emergency engine stop operation. (See SERVICE CAUTIONS .)

Adjust the tire pressure to the specification. (See WHEEL AND TIRE SPECIFICATION .)

Using a speedometer tester, verify that the values are as indicated in the table. km/h

Speedometer indication (km/h)	Speedometer tester indication (km/h)
20	17.57-22.43
40	37.67-42.33
60	57.57-62.43
80	77.47-82.53
100	97.12-102.88
120	116.66-123.34
140	136.37-143.63
160	156.37-163.63
180	176.37-183.63
200	196.20-203.80
220	215.40-224.60

SPEEDOMETER SPECIFICATIONS

Speedometer indication (mph)	Speedometer tester indication (mph)
10	9.07-10.92
20	19.10-20.89
30	29.07-30.92
40	39.03-40.95
50	48.98-51.00
60	58.85-61.13
70	68.693-71.277
80	78.579-81.387
90	88.577-91.385
100	98.58-101.38
110	108.58-111.38
120	118.51-121.44
130	128.41-131.53
140	138.41-141.53

If not as indicated in the table, perform the DTC inspection for the PCM and DSC HU/CM, and inspect the related wiring harnesses. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)] .) (See DTC INSPECTION [DSC HU/CM] .)
- If the PCM, DSC HU/CM, and related wiring harnesses are normal, replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION .)