Computed Timing Check

Turn ignition off, and wait 10 seconds. Using jumper wire or test equipment, activate KOER SELF-TEST. Start engine, and check following:

• If engine starts and stalls, or stalls during self-test, go to CIRCUIT TEST S.
• If Code 998 is displayed, EEC-IV system is operating in Failure Mode Effects Management (FMEM). Vehicle cannot be diagnosed in KOER SELF-TEST. Rerun KOEO SELF-TEST.
• Check computed timing after last service code has been displayed. Timing will remain fixed for 2 minutes after last code has been retrieved unless self-test is deactivated.
• Computed timing at crankshaft should equal base timing (10 degrees BTDC) plus 20 degrees BTDC. This timing may vary 3 degrees. If computed timing is within specification, perform KOER SELF-TEST. If timing is not within specification, go to CIRCUIT TEST P, step 2).