The EBCM performs self-diagnostics of the ABS. The EBCM
detects and isolates system malfunctions. When a malfunction is detected,
the EBCM sets a corresponding diagnostic trouble code (DTC).
Malfunction Response
ABS response to malfunctions falls into four classes:
| • | Permanent Latched Malfunction Response:
This means that the ABS is disabled and the ANTILOCK indicator lamp
is requested on (whenever the ignition is turned on) even if the cause of
the malfunction goes away. The only way to restore normal ABS operation is
to take the vehicle to an authorized service center to have the cause of the
malfunction corrected and the system reset by an electronic command sequence. |
| • | Ignition Latched Malfunction Response:
This means that the ABS is disabled and the ANTILOCK indicator lamp
is requested on until the ignition is turned off even if the cause of the
malfunction goes away. When the ignition is turned on again, the ABS will
not be disabled unless/until a subsequent malfunction is detected. |
| • | Condition Latched Malfunction Response:
This means that the ABS is disabled and the ANTILOCK indicator lamp
is requested on only as long as the apparent malfunction condition persists.
Normal ABS operation resumes automatically and the ANTILOCK indicator is requested
off as soon as the problem goes away; no service is necessary. The vehicle
operator may choose, without being prompted further by the ANTILOCK indicator
lamp, to take the vehicle to an authorized service center. |
| • | Information Only Malfunction Response:
This means that the ABS is not disabled and no indicator lamp is
requested for this malfunction. ABS activity continues as it was before this
malfunction occurred. |
DRP response to malfunctions falls into three classes:
| • | DRP Critical Malfunction Response:
This means that the DRP system is disabled and the BRAKE indicator
lamp is requested on. The DRP malfunction is latched the same as the ABS one
is for a given malfunction (Permanent, Ignition, and Condition latched), i.e.
a malfunction that is Ignition Latched for ABS activity is also ignition latched
for DRP activity. |
| • | DRP Non-Critical Malfunction Response:
This means that if more than one of these malfunctions are detected,
then DRP is disabled and the BRAKE indicator lamp is requested on. The DRP
malfunction is latched the same as the ABS one is for a given malfunction
(Permanent, Ignition, and Condition latched), i.e. a malfunction that is Ignition
Latched for ABS activity is also ignition latched for DRP activity. All Keep
Alive malfunctions are counted separately for purposes of DRP Keep Alive except
for sensor malfunctions. All the sensor malfunctions for a particular wheel
are counted as a single Keep Alive malfunction, i.e. a DTC C0221 and C0222
are considered one Keep Alive malfunction. |
| • | Information Only Malfunction Response:
This means that the DRP is not disabled and no indicator lamp is
requested for this malfunction. DRP activity continues as it was before this
malfunction occurred. |
