Download MIL ‘ON’ with DTC P1320 stored in the ECM • Intermittent spark knock (detonation) The trigger may be a number of of the ignition coils. Refer to the Service Procedure below to resolve the incident, if it ought to occur. SERVICE PROCEDURE Decide if one or both of the signs listed above exists and carry out the appropriate process(s) listed below. Procedure for MIL ‘ON’ with DTC P1320 Symptom 1. Test Self Diagnosis Outcomes (using CONSULT-II) to substantiate DTC P1320 (Ignition Signal Major) is stored within the ECM. NOTE: Single or multiple cylinder misfire codes (P0300 – P0306) could also be stored within the ECM with DTC P1320. 2. Test the ECCS wiring harness for a damaged or broken wire. A. If the ECCS harness has a damaged or damaged wire that’s inflicting the symptom(s) famous above, repair the harness and confirm the incident is resolved.