Computers and Control Systems: Adjustments

NOTE: Before idle speed check and adjustment, inspect for the following:

^ Inspect lead wires and hoses of MFI and engine emission control systems that they are connected securely.
^ Inspect accelerator cable to ensure that it has play and that it is NOT adjusted too tight.
^ Check ignition timing and adjust to specification if needed.
^ Check that all accessories (wipers, heaters, lights, etc.) are "OFF" or out of service.
^ Check the air cleaner for proper installation and ensure it is clean and in good condition.

PROCEDURE:

NOTE: Before starting the engine, place the transmission gear shift lever in NEUTRAL (shift selector lever to PARK for vehicles with A/T), and set the parking brake and block drive wheels.

1. Warm up engine to normal operating temperature, with all accessories OFF.

Description:

2. Connect scan tool (set to Engine Speed and ISC mode.) Remove adjusting screw cover.

Idle Air Control Valve:

3. Connect a jumper from the diagnostic request terminal 2 in the duty check data link connector to ground, terminal 4.
5. Check to ensure that idle speed, and ISC duty is within specification. Specification: 800 ± 50 rpm. ISC duty 50%.
6. If the idle is not within specified range, adjust it by turning the adjusting screw.

Idle Speed Settings:

7. Turn the A/C switch and blower speed selector switch ON. Perform steps 5 and 6 again.
8. Remove jumper from duty check DLC, and remove Scan tool. Install idle speed adjusting screw cover.