C1 - Check Base Timing

WARNING: Never connect PCM to EEC breakout box when performing EI diagnostics.

^ Key off.

^ Install EI (High Data Rate) diagnostic harness to breakout box and to both the ICM and vehicle harness. Do not connect the CKP sensor tee or coil tee.

^ Use EI (High Data Rate) 4 overlay.

^ Connect EI diagnostic harness negative and positive leads to battery.

^ Set EI diagnostic harness type switch to "4/6 cylinder" position.

^ Connect timing light (must be EI compatible).

^ Start engine and allow it to warm up.

^ Is timing 10° ± 2° BTDC when the EI diagnostic harness SPOUT button is pushed and held down (opens SPOUT circuit)?

YES -- GO to C2. C2 - Check For Spark Angle Advance

NO -- GO to C8. C8 - Inspect CKP Sensor and Trigger Wheel - Timing Fault