Computed Timing Check

Turn key off and wait 10 seconds. Using jumper wire or test equipment, activate KOER SELF-TEST . Start engine. Check the following items:

• If engine starts and stalls, or stalls during self-test, go to TEST S, step 1.
• If Code 98 is displayed, it indicates EEC-IV system is operating in Failure Mode Effects Management (FMEM). Vehicle cannot be diagnosed in KOER SELF-TEST; go to Code 98 reference in CONTINUOUS MEMORY CODE reference chart.
• Check computed timing after the last service code has been displayed. The timing will remain fixed for 2 minutes after the last code has been received, unless self-test is deactivated.
• Computed timing, at the crankshaft, should equal the base timing (see vehicle emission decal) 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 TEST P, step 2.