RAM 2500 Truck 4WD V8-5.9L VIN Z LDC (1998)
Emissions Maintenance Light: Description and Operation
SYSTEM OPERATION
The Maintenance Required or Service Reminder Indicator (SRI) lamp is used on certain vehicles equipped with a heavy-duty emissions cycle
package. This lamp is intended to provide a reminder that certain scheduled vehicle emissions services and maintenance must be performed, as
required by federal emissions laws.
The SRI lamp is turned on for about two seconds when the ignition switch is turned to the On position as a bulb test. After the bulb test, the
instrument cluster circuitry controls the lamp based upon status messages received from the Powertrain Control Module (PCM) on the Chrysler
Collision Detection (CCD) data bus. The PCM uses a distance pulse input received from the Controller Anti-lock Brake (CAB) and internal
programming to decide what status messages are required. The PCM then sends the proper messages to the instrument cluster circuitry on the CCD
data bus.
This lamp is not intended to indicate a warning, or that a state of emergency exists. However when the lamp has been activated, the required
services and maintenance must be performed before the lamp can be legally reset.
