RAM 2500 Truck 2WD L6-5.9L DSL Turbo VIN 6 (1998)
Wait To Start Light: Description and Operation
SYSTEM OPERATION
Vehicles equipped with an optional diesel engine have a wait-to-start lamp. The wait-to-start lamp gives an indication that the conditions for
easiest starting of the diesel engine have not yet been achieved. The wait-to-start lamp bulb in the instrument cluster is lighted by the Powertrain
Control Module (PCM) after the ignition switch is turned to the On position.
One side of the wait-to-start lamp bulb receives battery voltage when the ignition switch is turned to the On position. The PCM switches the
ground path for the other side of the bulb based upon several inputs and its internal programming.
The wait-to-start lamp lets the driver know that the intake manifold air heater grid has had sufficient time to warm the intake air for a good quality
start. The intake manifold air preheat cycle is controlled by an electronic air heater control module. The lamp will be turned off by the PCM when
the heater control module cycle is completed, or if the driver turns the ignition switch to the Start position prior to the end of the heater control
module cycle.
