Diagnostic Trouble Code (DTC) Type Definitions

Diagnostic Trouble Code (DTC) Type Definitions

Emissions Related DTCs

Action Taken When the DTC Sets - Type A

The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

Action Taken When the DTC Sets - Type B

The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.

Action Taken When the DTC Sets - Type B1

* The following applies to misfire DTCs:

- If the control module detects a low level or an emission level misfire condition during 2 consecutive trips, the control module illuminates the MIL.

- If the control module detects a high level or catalyst damaging misfire, the control module flashes the MIL at a rate of once per second.

- If the control module detects a misfire during 2 non-consecutive trips, the stored conditions are compared with the current conditions. The control module illuminates the MIL when the following conditions occur:

* The engine load is within 10 percent of the previous test that failed.

* The engine speed is within 375 RPM of the previous test that failed.

* The engine coolant temperature is in the same range of the previous test that failed.

* The following applies to fuel trim DTCs:

- If the control module detects a fuel trim condition during 2 consecutive trips, the control module illuminates the MIL.

- If the control module detects a fuel trim condition during 2 non-consecutive trips, the stored conditions are compared with the current conditions. The control module illuminates the MIL when the following conditions occur:

* The engine load is within 10 percent of the previous test that failed.

* The engine speed is within 375 RPM of the previous test that failed.

* The engine coolant temperature is in the same range of the previous test that failed.


Conditions for Clearing the MIL/DTC - Type A or Type B

* The control module turns OFF the MIL after 3 consecutive ignition cycles, when the diagnostic runs and passes.

* An active DTC clears when the diagnostic runs and passes.

* A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

* 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 control module stores the DTC information into memory when the diagnostic runs and fails.

* The MIL will not illuminate.

* The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC - Type C

* A last test failed, or active DTC, clears when the diagnostic runs and passes.

* Use a scan tool in order to clear the DTC.