Start and warm engine to normal operating temperature. Shut engine off. Connect timing light to spark plug wire on cylinder No. 1 (front cylinder at timing belt end of engine). Remove cover and connect scan tester to data link connector No. 3. See Fig 1. Scan tester is used to read engine RPM.
Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 of data link connector No. 1. See Fig 2.
Apply parking brake. Place transaxle in Neutral. Start engine and maintain engine at 1000-1500 RPM for 5 seconds and then ensure engine returns to idle.
NOTE: Timing marks are located on front cover.
Ensure base timing is within specification at idle with transaxle 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 tester.

IGNITION TIMING (Degrees BTDC @ Idle) ⁽¹⁾

Application Type

⁽²⁾ Base Timing

⁽³⁾ ECM Controlled Timing

Tercel

7-17

⁽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 Tester

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Ignition Timing