| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
Circuit  | Short to Ground  | High Resistance  | Open  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|---|
Ignition Coil 1 Control Circuit  | P0351  | P0351  | P0351  | P0351  | P0351  | 
Ignition Coil 2 Control Circuit  | P0352  | P0352  | P0352  | P0352  | P0352  | 
Ignition Coil 3 Control Circuit  | P0353  | P0353  | P0353  | P0353  | P0353  | 
Ignition Coil 4 Control Circuit  | P0354  | P0354  | P0354  | P0354  | P0354  | 
The ignition system uses individual ignition coil/module assemblies for each cylinder. The engine control module (ECM) controls the individual coils by transmitting timing pulses on the ignition control (IC) circuit of each ignition coil/module to enable a spark event. The ECM monitors each IC circuit for improper voltage levels. Each ignition coil/module has the following circuits:
| • | An ignition voltage circuit | 
| • | A ground | 
| • | An IC control circuit | 
| • | A low reference circuit | 
| • | The engine is running. | 
| • | DTCs P0351-P0354 runs continuously when the above condition is met. | 
| • | The ECM detects an open on the circuit or the ignition coil/module for less than 1 second. | 
| OR | 
| • | The ECM detects a short to ground on the circuit or the ignition coil/module for less than 1 second. | 
| OR | 
| • | The ECM detects a short to voltage on the circuit or the ignition coil/module for less than 1 second. | 
DTCs P0351-P0354 are Type B DTCs.
DTCs P0351-P0354 are Type B DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
| • | Start and idle the engine. | 
| • | Observe the scan tool DTC Information and the Misfire Current Cyl. parameters. This will indicate the affected ignition coil/modules, and if the condition is current. | 
Important: A high resistance on any IC circuit can cause a misfire before the DTC sets.
| ⇒ | If a fault is found, repair the circuit as needed. | 
| ⇒ | If the DTC or the misfire transfers with the suspect ignition/coil module, replace as needed. | 
| ⇒ | If the DTC or the misfire does not transfer with the suspect ignition/coil module, replace the ECM. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |