Ignition Timing: Adjustments

BASE TIMING
The base ignition timing is determined by the relationship of the crankshaft position sensor to the crankshaft reluctor ring. This relationship is not adjustable and results in the base ignition timing of 10° BTDC.

SPARK CONTROL OVERRIDE
The PCM incorporates a permanent spark control override, PS22, which allows base ignition timing to be lowered electronically if spark knock is encountered during normal operation due to the use of low octane fuel.

BASE TIMING ADJUSTMENT
Base ignition timing can be lowered using this override down to 6° BTDC. This override is stored in PCM memory and will remain at the set timing unless the battery is disconnected. To reset permanent spark override:

1. Key "ON", enter diagnostics.
2. Select PCM override PS22 (SERVICE SPK).
3. Press "COOLER" button to lower ignition base timing and press "WARMER" button to increase ignition base timing.