Powertrain 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. |
• |
The control module records the
operating conditions at the time the diagnostic fails. The control
module stores this information in the Freeze Frame/Failure
Records. |
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. |
• |
The control module records the
operating conditions at the time the diagnostic fails. The first
time the diagnostic fails, the control module stores this
information in the Failure Records. If the diagnostic reports a
malfunction on the second consecutive ignition cycle, the control
module records the operating conditions at the time of the
malfunction. The control module writes the operating conditions to
the Freeze Frame and updates the Failure Records. |
• |
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 20% 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 20% 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 4 consecutive ignition cycles that the diagnostic
runs and does not fail. |
• |
A current DTC, Last Test
Failed, clears when the diagnostic runs and passes. |
• |
A history DTC clears after 40
consecutive warmup cycles, if no malfunctions are reported by this
or any other emission related diagnostic. |
• |
Clear the MIL and the DTC with
a scan tool. |
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 control module records the
operating conditions at the time the diagnostic fails. The control
module stores this information in the Failure Records. |
• |
The driver information center,
if equipped, may display a message. |
Conditions for Clearing the DTC - Type C
• |
A current DTC Last Test Failed
clears when the diagnostic runs and passes. |
• |
A history DTC clears after 40
consecutive warmup cycles, if no malfunctions are reported by this
or any other non emission related diagnostic. |
• |
Clear the DTC with a scan
tool. |
Action Taken When the DTC Sets - Type D
• |
The control module will take
default actions but no DTC will be stored in Failure
Records. |
• |
The MIL or SVS will not
illuminate. |
Conditions for Clearing the DTC - Type D
Clear the DTC with a scan tool.
|