Emissions Related DTCs
Action Taken When the DTC Sets - Type A
The engine control module (ECM) illuminates the malfunction indicator lamp (MIL)
when the diagnostic runs and fails.
Action Taken When the DTC Sets - Type B
The engine control module (ECM)i illuminates the MIL on the second consecutive
ignition cycle that the diagnostic runs and fails.
Conditions for Clearing the MIL/DTC - Type A or Type B
| • | The ECM turns OFF the MIL after 3 consecutive ignition cycles that
the diagnostic runs and does not fail. |
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | Use a scan tool in order to clear the MIL and the DTC. |
Non-Emissions Related DTCs
Action Taken When the DTC Sets - Type C
| • | The ECM stores the DTC information into memory when the diagnostic runs
and fails. |
| • | The MIL will not illuminate. |
| • | The driver information centre, if equipped, may display a message. |
Conditions for Clearing the DTC - Type C
| • | A last test failed, or current DTC, clears when the diagnostic runs and
passes. |
| • | Use a scan tool in order to clear the DTC. |
Conditions for Clearing the DTC - Type X
This DTC is available in the ECM software, but has been disabled, or turned
OFF. In this case, the diagnostic does not run, no DTCs are stored, and the MIL does
not illuminate. Type X DTCs are used primarily for export vehicles that do
not require MIL illumination or DTC storing.
