Engine - Excessive White Smoke On Start Up
NO.: 08-05-93GROUP: Electrical
DATE: Feb. 8, 1993
SUBJECT:
Diesel - White Smoke On Start Up
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A DIESEL ENGINE BUILT AFTER MDH 10-01-XX.
MODELS:
1993 (AD) Ram Pickup/Ram Cab Chassis
SYMPTOM/CONDITION:
Some new vehicles or vehicles which have had a service Powertrain Control Module (SBEC) installed, may exhibit excessive white smoke upon cold engine start up.
DISCUSSION:
Changes to the Powertrain Control Module programming were made to prolong battery life during the storage and shipment of new vehicles. The change eliminated the operation of the air intake heaters after the engine started for the first 25 vehicle starts. The air intake heaters have a very high current draw when they are activated. The function of the air intake heaters, after start up, is to reduce white smoke on cold engine starts.
There may be situations where vehicles will arrive at dealerships which have not accumulated 25 starts. In these cases the vehicles may exhibit excessive white smoke. The condition may also exist after a Powertrain Control Module has been replaced with a service part. This condition is normal and will be eliminated after 25 starts have been achieved.
POLICY:
Information Only