| • | 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  | Open/High Resistance  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|
Ignition 1 Signal  | P0562  | P0562  | --  | --  | 
The engine control module (ECM) monitors the ignition voltage on the ignition feed circuit to terminal 39 at the ECM. A system voltage DTC will set whenever the voltage is below a calibrated value.
Engine running time is greater than 120 seconds.
System voltage is between 2.48-10.01 volts.
| • | The malfunction indicator lamp MIL will be illuminated after 3 valid driving cycles. | 
| • | The ECM will record operating conditions at the time of the diagnostic failure. This information will be stored in the Freeze Frame and Failure Records buffers. | 
| • | A history DTC is stored. | 
| • | The MIL will turn OFF after 3 or 4 consecutive driving cycles in which the diagnostic runs without a fault. | 
| • | A history DTC will clear after 40 consecutive warm up cycles without a fault. | 
| • | DTCs can be cleared by using the scan tool. | 
| • | Disconnecting the ECM battery feed for 10 seconds | 
With the scan tool installed, ignition ON and the engine OFF, observe the Ignition 1 Signal parameter in the ECM data list. The Ignition 1 Signal parameter should read 10.5 volts or greater.
| ⇒ | If greater than 1 volt test the ignition 1, ground circuits of the ECM for open/high resistance or replace the ECM. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming