Idle Speed

NOTE: Because the idle speed is controlled automatically by the engine control unit through the idle speed control (ISC) solenoid valve, usually it is not necessary to check and adjust the idle speed.


1. Warm up the engine to normal operating temperature, and check the condition of the engine (spark plugs, leaks in hoses, etc.).
2. Turn all electrical loads OFF.

Fig. 17 Diagnostic Connector:

3. Connect the MAZDA SPECIAL SERVICE TOOL #49 B019 9A0 to the diagnosis connector.

Note: If the SST is not used, jump across the TEN terminal and the GND terminal of the diagnostic connector.

Caution: Be extremely careful when making connections to the diagnosis connector as a mistaken connection will cause a malfunction. If the power connector terminal is grounded (Blue: 1-pin); the wiper 20A fuse will be burned.

Fig. 15 Test Connector Blue:

Fig. 16 Test Connector IG -:

Note: When using an externally powered tachometer and/or timing light connect it to the power connector located in the left front of the engine compartment (connector B1-11, blue: 1-pin).

4. Connect a tachometer to the diagnosis connector IG- terminal.
5. Set SST switch "A" to position 1.
6. Set TEST SW to SELF-TEST.
7 Apply parking brake.
8. Check that idle speed is within specification.

IDLE SPEED
850 ± 50 rpm (Neutral or P range)

Fig. 20 Idle Adjustment:

9. If not within the specification, remove the blind cap from the air adjusting screw and adjust the idle by turning the air adjusting screw.
10. After adjusting the idle speed, install the blind cap and Disconnect the SST, or jumper wire.