Computed Timing Check

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

• If engine starts and stalls, or stalls during self-test, go to TEST S, step 1).
• If Code 98 or 998 is displayed, it indicates 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 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 step 2) of TEST PA for TFI ignition vehicles (all except 3.8L SPFI SC). If timing is not within specification on DIS models, go to step 2) of TEST PB (3.8L SPFI SC).