
Diagnostic Procedure

Dtc 21
Dtc 58Mazda 6 Service Manual: Instrument cluster inspection
Speedometer
Using the input/output check mode
Inspect the speedometer by setting it in the input/output check mode DTC 12.
Using a speedometer tester
1. Adjust the tire air pressure to the specification.
2. Using a speedometer tester, verify that the speedometer indication is
within the allow ...
Mazda 6 Service Manual: No. 1 one or more on-board diagnostic functions inoperative
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunctions. If there
is a problem, check to make sure connectors, terminals and wir ...