Basic Idle Speed
NOTE:
Ensure vehicle is at normal operating temperature with all lights, cooling fan and accessories off. Shift transmission into Neutral or Park position.
NOTE:
Basic idle speed should only be adjusted after verifying that spark plugs, fuel injectors, idle air control motor and engine compression are okay.
- Basic idle speed can only be adjusted using a scan tool to ground Data Link Connector (DLC). Connect scan tool to DLC. DLC is located below dash, near steering column.
- Start engine and allow it to idle. Using scan tool, select MFI SYSTEM ACTUATOR TEST, then select item 30. Check basic idle speed. See IDLE SPEED SPECIFICATIONS
table.CAUTION: MFI system actuator test must be cancelled or test will continue to run for 27 minutes. Driving vehicle under this condition may damage engine.
- Cancel MFI system actuator test. If idle speed is not within specification, turn engine speed adjusting screw until correct engine speed is obtained. See Fig 1 . Access to speed adjusting screw is obtained by removing rubber plug on throttle body.
- If idle speed cannot be lowered by turning engine speed adjusting screw, determine if fixed Speed Adjusting Screw (SAS). Fixed SAS is stop screw contacting throttle lever. See FIXED SPEED ADJUSTING SCREW for procedure.
- After all adjustments are verified to be correct, possible cause of incorrect idle speed is deterioration of Idle Air Control (IAC) circuit. See DTC P0505 in TESTS W/CODES
article.IDLE SPEED SPECIFICATIONS
Application Curb Idle Basic Idle 3.5L 600-800 650-750