Try Mil Watching To Read Readiness Code Status (HSN 1002-03)

TRY MIL WATCHING TO READ READINESS CODE STATUS

TECHNICAL SERVICE BULLETIN

SERVICE INFORMATION

Readiness codes (also called diagnostic readiness codes or readiness/function codes) tell you if a specific emissions control system monitor has completed all testing needed to determine the operational status of the related system. This process of testing until the operational status is determined is referred to in OBD II lingo as "monitoring" the emissions control system.

You can check readiness code status by watching the MIL on the gauge assembly or using the PGM Tester. If you don't want to hassle with the PGM Tester, MIL watching is the way to go. Just turn the ignition switch to ON (II) (but don't start the engine), and keep your eyes on the MIL. If all readiness codes are complete, the MIL comes on for 20 seconds and then goes off. If one or more codes are incomplete, the MIL comes on for 20 seconds and then blinks five times.

Want to beef up your knowledge of readiness codes? Visit the Online University on the Interactive Network (iN), and order up EMC48, OBD II Readiness Codes Operation. (You'll see this module listed as READINESS CODES in the menu.) This module covers the system. The module is in Adobe PDF format, so it's a snap to print out if you prefer to study from a hard copy.