Detonation Condition

1. Drive the vehicle until engine temperature is stabilized.

2. Idle the vehicle for 15-25 minutes.

3. Using NGS Tester, verify ECT reads above 99°C (210°F) and Air Charge Temperature (ACT) reads above 60°C (140°F). If the ECT and ACT will not reach these temperatures, accelerate the engine at heavy throttle 3-4 times to raise the ECT and ACT and then repeat the extended idle. If the ECT and ACT still do not reach the desired temperatures, the ambient temperature is not high enough.

4. With the engine and underhood hot, drive the vehicle between 1000 to 1500 rpms in 4th gear. Tip-in to a moderate throttle position and listen for detonation. Repeat at least 5 times.





5. If detonation is heard, reprogram the PCM using the latest update CD-ROM. Refer to the PCM Application Chart for correct PCM usage.