Engine Controls - Extended Idling In Cold Weather: Overview
NUMBER: 18-019-01GROUP: Vehicle Performance
DATE: September 3, 2001
SUBJECT:
Cold Idle Engine Warming
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the Engine Control Module (ECM) with new software (Cal 55T1 8, 57T11, 56T13, 59T7b, and 59T8b.)
MODELS:
1998-1/2 - 2002 BR/BE Ram Trucks
NOTE:
THIS BULLETIN APPLIES TO ALL RAM TRUCKS BUILT AFTER DECEMBER 17, 1997 AND EQUIPPED WITH THE 24-VALVE 5.9L CUMMINS DIESEL ENGINE.
SYMPTOM/CONDITION:
Extended idle operation, especially in cold weather, can lead to stuck valves and bent push-tubes due to insufficient cylinder heat. This allows varnishes/oils to condense on the exhaust valve stems, leading to stuck valves, and damaged valve train components. A new software feature, enabled or disabled through the DRBIII(R) (See instructions under Repair Procedure), reduces the chance of valve sticking and improves cab heat warm-up time.
Once enabled, idle speed will slowly ramp up from 800 rpm to 1200 rpm when all of the following conditions are met:
1. Intake Manifold Temperature less than 0°C (32°F) and,
2. Coolant Temp is less than 60°C (140°F) and,
3. The Transmission is in Neutral or Park and,
4. The Service Brake pedal is not depressed and,
5. Throttle = 0% and,
6. Vehicle Speed = 0 mph
Additionally, if Intake Manifold Temperature (IMT) is less than -9°C (15°F), and all of the parameters above are met, three of the cylinders will be shut off upon reaching 1200 rpm, creating a slight change in engine sound which is normal. This allows the engine to create increased heat in the cooling system, allowing more rapid engine warm up and cab heating.
Both features will automatically disable when one of the following occurs:
1. The Automatic Transmission is placed in gear (forward or reverse) or,
2. The Service Brake pedal is depressed or,
3. Throttle position is greater than 0% or,
4. Vehicle Speed is greater than 0 mph or,
5. Coolant Temperature is greater than 79°C (175° F).
Engine speed will return to normal operation at 800 rpm. If the engine continues to idle and coolant temperature is at or below 60°C (140°F), the feature will reenable. In order to operate properly, the Accelerator Pedal Position Sensor (APPS) must stay at idle.
NOTE:
ANY TYPE OF AFTERMARKET IDLE SPEED KICKER THAT ACTIVATES THE APPS WILL DISABLE THIS FEATURE.
Use of the 110V block heater will not allow the feature to function after an overnight soak. If the vehicle is left idling, without use of the block heater, 1200 rpm operation will begin when the intake temperature drops below 0°C (32°F) and coolant is less than 60°C (140°F).
DIAGNOSIS PROCEDURES:
1. Using the Diagnostic Scan Tool (DRBIII(R)) with the appropriate Diagnostic Procedures, verify all engine/transmission systems are functioning as designed. If other Diagnostic Trouble Codes (DTC) are present, record them on the repair order and repair as necessary before proceeding further with this bulletin.
PARTS REQUIRED:
EQUIPMENT REQUIRED:
NOTE:
THE MDS2 AND DRB III(R) ARE REQUIRED TO PERFORM PART OF THIS REPAIR.
WHEN USING THE MDS2 AND THE DRB III(R), THE SYSTEM MUST BE OPERATING AT CIS CD 2090 OR HIGHER (2090 ARRIVES IN DEALERSHIPS ON SEPTEMBER 3, 2001).
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
FAILURE CODE: