DTC's are categorized by type. The DTC type relates to
how the MIL operates and how the fault data is stored when a particular DTC
fails. In some cases there may be exceptions to this structure. Therefore,
it is important to read the Action Taken When the DTC Sets and Conditions
for Clearing the MIL/DTC in the supporting text when diagnosing the system.
The following list describes the general characteristics of each DTC
type:
| • | Type A DTCs are emissions related. The PCM performs the following
actions at the time of the first fail: |
| - | Stores the DTC in memory |
| - | Captures Freeze Frame/Failure Records data |
| • | Type B DTCs are emissions related. The first fail and any subsequent
failures are handled differently. |
| - | The PCM performs the following actions at the time of the first
fail: |
| • | Does not turn on the MIL |
| • | Stores the DTC in memory as Failed Last Test |
| • | Captures Freeze Frame/Failure Records data |
| - | The PCM performs the following actions at the time of the second
fail if the fault is active for 2 consecutive driving cycles: |
| • | Stores the DTC in memory (the DTC will now appear in History) |
| • | Updates Freeze Frame/Failure Records data |
| - | The PCM performs the following actions at the time of a second
failure that is not on a consecutive trip: |
| • | Does not turn on the MIL |
| • | Stores the DTC in memory as Failed Last Test |
| • | Updates Failure Records data only |
| • | Type C DTCs are not emissions related. The PCM performs the following
actions at the time of the first fail: |
| - | Does not turn on the MIL |
| - | Stores the DTC in memory |
| - | Captures Failure Records data |
| - | Some Type C DTCs may also turn on an auxiliary service lamp, and/or
cause a message to be displayed on the Driver Information Center (DIC) depending
on how the vehicle is equipped. The lamp/message request occurs at the
time of the first fail. Type C DTCs that do not turn on a lamp or send
a message were formerly referred to as Type D. |
