Minimum Air Rate - Fuel Injection Only

CONTROLLED IDLE SPEED CHECK

1. Set parking brake and block drive wheels.

2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode.

3. START engine and bring it to normal operating temperature.

4. Check for correct state of PARK/NEUTRAL switch on SCAN tool.

5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts).

6. If within specifications, the idle speed is being correctly controlled by the ECM.

7. If not within specifications, perform MINIMUM IDLE AIR RATE CHECK. If still not within specifications, refer to DIAGNOSIS BY SYMPTOM/DIAGNOSIS AND TESTING PROCEDURES/ROUGH, UNSTABLE OR INCORRECT IDLE.

MINIMUM IDLE AIR RATE CHECK

Minimum Idle Air Rate is not adjustable on this engine.

UNDER 8500 GVW

CONTROLLED IDLE SPEED

Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2]

Man. N 550 2-20 CL

Auto D 537 5-30 CL

[1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level.

[2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop).

MINIMUM IDLE AIR RATE CHECK

Minimum Idle Air Rate is not adjustable on this engine.

OVER 8500 GVW

CONTROLLED IDLE SPEED

Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2]

Man. N 650 5-30 CL

Auto D 650 20-35 CL

[1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level.

[2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop).

MINIMUM IDLE AIR RATE CHECK

Minimum Idle Air Rate is not adjustable on this engine.