Using A DMM

IMPORTANT: Before starting the engine, place the manual selector in P (automatic transaxle) or place the gearshift control lever in neutral (manual transaxle), set the parking brake and block the drive wheels.

Check following for correct condition and operation.
- Check the accelerator cable for free movement and excessive play. Cable free play should be within specification.
- Inspect the lead wires and the hoses of the Sequential Multiport Fuel Injection (SFI) and the Evaporative Emission (EVAP) control systems for being connected securely.
- Check the ignition timing. Adjust the ignition timing if necessary.
- Turn OFF all accessories (A/C, wipers, heater, lights, etc.).
- Make sure that the Air Cleaner (ACL) is installed correctly.
- Check the Air Induction system for restrictions.
- Check the vacuum hoses for correct routing. Refer to the Emission Label.
- Check for vacuum leaks, repair as necessary.

IMPORTANT:
The Idle Air Control (IAC) Calibration Mode is an internal function in the PCM, and is used to provide a base duty cycle. Therefore, when the vehicle is in the IAC Calibration Mode (terminal 2 and 4 are jumpered on the Duty Check Data Link Connector) the IAC Duty Cycle will read approximately 50% and may seem to be out of specifications, this should be considered normal operation. When the AC Duty is OFF, the DMM will read approximately 100% (0 volts).

When setting the IAC Duty, the duty cycle must be ON to obtain the correct reading. If the IAC Duty remains unchanged when the adjusting screw is turned, check the duty output terminal circuit, A/C signal circuit, PSP switch signal circuit, PNP switch circuit (A/T) and ECT sensor performance.

Adjustment Procedure
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. Connect a tachometer.
4. Monitor the engine speed.




5. Connect a fused jumper wire from terminal 2 (diagnostic request ) to terminal 4 (ground) of the Duty Check Data Link Connector.
6. Connect a DMM (J-39200) from terminal 6 (duty check) to terminal 4 (ground) of the Duty Check Data Link Connector.

IAC Duty To Voltage Relation:

7. Check the idle speed and the AC duty on the DMM. The IAC duty should read 50 percent or 7 volts with the correct engine idle speed.

NOTE: In the "IAC Duty To Voltage Relation" table the battery voltage represents battery voltage when the vehicle is running.




8. Remove the plug over the IAC duty adjusting screw and adjust the idle speed by turning the IAC duty adjusting screw (1).
9. Remove the fused jumper wire from the duty check data link connector.
10. Disconnect the DMM from the duty check data link connector.
11. Disconnect the tachometer.
12. Install the plug over the AC duty adjusting screw.
13. Check that the specified idle speed is obtained with the A/C ON (If equipped with A/C).