Ignition Timing

Start and warm engine to normal operating temperature. Shut engine off. Connect timing light to spark plug wire on cylinder No. 1. Cylinder No. 1 is front cylinder on right side, viewed from flywheel end of engine. See Figure.
Connect scan tool to data link connector No. 3. See Fig 1. Scan tool is used to read engine RPM.
Apply parking brake. Place transmission in Neutral. Start engine and maintain engine at 1000 RPM for 5 seconds and then allow engine to idle. Ensure idle speed is 650-750 RPM.
Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1. See Fig 2. Data link connector No. 1 is located at center of air intake chamber on the engine.
NOTE: Timing marks are located on front cover.
Ensure base timing is within specification at idle with transmission in Neutral, and with A/C and all accessories off. See IGNITION TIMING table.
Remove jumper wire from data link connector No. 1. Ensure ECM controlled timing is within specification. See IGNITION TIMING table. Shut engine off. Remove jumper wire, timing light and scan tool.

IGNITION TIMING (Degrees BTDC @ Idle) ⁽¹⁾

Application

⁽²⁾ Base Timing

⁽³⁾ Controlled Timing

3.4L

8-12

3-19

⁽¹⁾	Check with engine at normal operating temperature, transmission/transaxle in Neutral, parking brake applied, electric cooling fan off (if equipped) and A/C and all accessories off.

⁽²⁾	With Jumper Wire (SST 09843-18020) installed between terminals TE1 and E1 on data link connector No. 1.

⁽³⁾	With jumper wire removed from data link connector No. 1.

Fig 1: Connecting Scan Tool

Fig 2: Installing Jumper Wire Between Data Link Connector No. 1 Terminals