Trouble Codes

Self-Diagnosis Checker (49 H018 9A1) must be used to obtain trouble codes. Warm engine to normal operating temperature. Connect self-diagnosis checker to connector. See Fig 1 .

Place select switch in the "B" position. Check trouble code number indicated. Compare trouble code to that listed. See TROUBLE CODE USAGE table. SELF-DIAGNOSIS under TROUBLE SHOOTING in this article for trouble shooting procedure.

NOTE: Self-diagnosis checker buzzer will activate for approximately 3 seconds after the ignition is turned on.

Fig 1: Installing Self-Diagnosis Checker

Courtesy of MAZDA MOTORS CORP.

TROUBLE CODE USAGE

Code	Probable Cause
01	Crank Angle Sensor
02	Airflow Meter
03	Coolant Thermosensor
04	Intake Air Temp. Switch (Located In Airflow Meter)
05	Oxygen Sensor
06	Throttle Sensor
07	Boost or Pressure Sensor
09	Atmospheric Pressure Sensor
12	Coil W/Ignitor (Trailing Side)
15	Intake Air Temp. Switch (Located in intake pipe or dynamic chamber)

Monitor light on self-diagnosis checker will test O2 sensor signal. Note light operation. Determine if air/fuel ratio is correct. See MONITOR LIGHT INDICATIONS table. Check feedback system if incorrect air/fuel ratio is indicated.

MONITOR LIGHT INDICATIONS

Light Operation	Air/Fuel Ratio
On	Too Rich
Off	Too Lean
Flashing	Best