The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
On rare occasions, a customer may complain of a misfire and SES light. Upon inspection, no spark from the ignition coils may be observed and any of the following DTCs may be stored: P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0351, P0352, P0353, P0354, P0355, P0356, P0357, and/or P0358.
Perform wiggle test the ignition coil harnesses to see if the concern can be duplicated. If so, the following areas could be causing an intermittent loss of ignition 1 voltage to the ignition coils and should be inspected:
- For C/K Trucks and Utilities, inspect S160, S159, C148, and C149 for poor connections. Also, inspect the circuits on both sides of C148 and C149 to see if any are broken inside of the insulation, especially the pink ignition 1 power feed circuit.
Essentially, first thing should be to check all your harness connectors for damage and make sure they are all tight. Unplug and replug them in and you can even spray them with a electrical contact cleaner such as Deoxit. That's the easiest thing to check first. Then other things like grounds if you live in a rust-zone.
Does your scanner give you any other details about the code? Is this the only code you have?