Emissions Control: Diagnosis RAM Pickup 1500

DIAGNOSIS AND TESTING - DIESEL EXHAUST FLUID

Scheme 44

Scheme 45

1. Clean the Diesel Exhaust Fluid (DEF) pump to remove contamination or debris by the fluid filter.
2. Remove the DEF filter cap (1).
3. Visually inspect the fluid for sign of contamination or debris.
4. Collect a sample of diesel exhaust fluid from the system.
5. Test the quality of the DEF using the DEF/UREA Refractometer 94-F-OOK-108-456 available through Pentastar Service Equipment or with a litmus test paper. The DEF should register approximately 32.5 percent using a refractometer or with litmus paper 9 pH.
6. If the DEF is not within specifications then the tank needs to be drained and cleaned and refilled with a minimum of 2.5 gallons good DEF.
7. Install the DEF filter cap (1). Tighten to (1) to 20 N.m (177 in. lbs).

DIAGNOSIS AND TESTING - CLOSED CRANKCASE VENTILATION (CCV)

1. If troubleshooting high crankcase pressure, the following items can be causing the closed crankcase ventilation valve to close during engine operation: A restricted crankcase ventilation filter. Change the filter A malfunctioning or incorrectly assembled closed crankcase ventilation valve. Check the valve operation.
2. The closed crankcase ventilation valve should allow crankcases gases to flow when the engine is not running and/or removed from the engine. NOTE: Application of air can be applied either to the inlet or outlet of the closed crankcase ventilation valve.
3. A small amount of air can be blown through the closed crankcase ventilation valve (less than 34 kPa [5 psi]) to check the closed crankcase ventilation valve.
4. If air does not go through the closed crankcase ventilation valve, replace the valve.

Scheme 46

1. If equipped, remove the engine cover.
2. Remove the breather hose (1) from the breather cover. CAUTION: The use of air tools is not recommended as damage to the component may result.
3. Remove the oil fill cap (3), the bolts (2) and the breather cover.
4. Remove the breather element (1) from the cylinder head cover (2).

Scheme 47

1. Inspect the Close Crankcase Ventilation System (CCV) by ensuring the oil drain hoses are not kinked or cracked.
2. Inspect the breather element sealing gasket (3) and surface area for gouges or cracks; this surface should be smooth and free of abrasions.

Scheme 48

Scheme 49

Scheme 50

1. Clean the filter sealing surface on the cylinder head cover (2) with a clean shop towel.
2. Install a new gasket (1) onto the cylinder head cover (2).
3. Apply clean engine oil to the two bottom O-ring (1) on the breather element (2) and install the new breather element onto the cylinder head cover.
4. Apply clean engine oil to the top O-ring (1) on the breather element (2). CAUTION: The use of air tools is not recommended as damage to the component may result.
5. Install the breather cover and the oil fill cap (3). Tighten bolts (2) to 10 N.m (89 in. lbs.).
6. Install the breather hose (1) onto the breather cover.
7. If equipped, install engine covers.

Test Sequence

In many instances, emissions systems must fail diagnostic tests more than once before the PCM illuminates the MIL. These tests are known as 'two trip monitors.' Other tests that turn the MIL lamp on after a single failure are known as 'one trip monitors.' A trip is defined as 'start the vehicle and operate it to meet the criteria necessary to run the given monitor.'

Many of the diagnostic tests must be performed under certain operating conditions. However, there are times when tests cannot be run because another test is in progress (conflict), another test has failed (pending) or the Task Manager has set a fault that may cause a failure of the test (suspend).

Diagnostic Trouble Codes (DTCs)

With OBD II, different DTC faults have different priorities according to regulations. As a result, the priorities determine MIL illumination and DTC erasure. DTCs are entered according to individual priority. DTCs with a higher priority overwrite lower priority DTCs.

Priorities

1. Priority 1 One-Trip Failure of Non-Fuel or Non-Mis-Fire Fault (e.g., Cat Mon Failure)
2. Priority 3 Matured Fault (either One-Trip or Two-Trip) Non-Fuel AND Non-Mis-Fire
3. Priority 4 One-Trip Failure of Fuel System or Mis-Fire Fault
4. Priority 6 Matured Fault for Fuel System or Mis-Fire (either One-Trip or Two-Trip)

Non-emissions related failures have no priority. One trip failures of two trip faults have low priority. Two trip failures or matured faults have higher priority. One and two trip failures of fuel system and misfire monitor take precedence over non-fuel system and non-misfire failures.

DTC Self Erasure

With one trip components or systems, the MIL is illuminated upon test failure and DTCs are stored.

Two trip monitors are components requiring failure in two consecutive trips for MIL illumination. Upon failure of the first test, the Task Manager enters a maturing code. If the component fails the test for a second time the code matures and a DTC is set.

After three good trips the MIL is extinguished and the Task Manager automatically switches the trip counter to a warm-up cycle counter. DTCs are automatically erased following 40 warm-up cycles if the component does not fail again.

For misfire and fuel system monitors, the component must pass the test under a Similar Conditions Window in order to record a good trip. A Similar Conditions Window is when engine RPM is within ±375 RPM and load is within ±20% of when the fault occurred.

Note. It is important to understand that a component does not have to fail under a similar window of operation to mature. It must pass the test under a Similar Conditions Window when it failed to record a Good Trip for DTC erasure for misfire and fuel system monitors.

DTCs can be erased anytime with a scan tool. Erasing the DTC with the scan tool erases all OBD II information. The scan tool automatically displays a warning that erasing the DTC will also erase all OBD II monitor data. This includes all counter information for warm-up cycles, trips and Freeze Frame.