JC41 - Check C4 at Coil Connector While Cranking

- Connect an incandescent test lamp between J1 (B+) and J18 (LC4C).

- Crank engine.

- Does lamp blink consistently and brightly (one blink per engine revolution)?

YES -- REPLACE left coil pack. Input to coil pack is OK, but no high voltage output. REMOVE all test equipment. RECONNECT all components. Clear continuous memory. Clearing Diagnostic Trouble Codes

Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes

NO -- REPLACE ICM. C4 open in ICM. REMOVE all test equipment. RECONNECT all components. Clear continuous memory. Clearing Diagnostic Trouble Codes

Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes