GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Silverado - 4WD 🢒 DTC 🢒 DTC P244C

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P244C: Catalyst Temperature Too Low During Regeneration

Circuit/System Description

The diesel oxidation catalyst (DOC) converter controls emissions of non methane hydro carbons (NMHC), and soluble organic fraction (SOF). The DOC is also utilized in regenerating the exhaust particulate filter (EPF). The engine control module (ECM) monitors the exhaust gas temperature (EGT) sensor 1 during regeneration to determine if regeneration temperatures can be maintained.

If the ECM detects that the DOC cannot maintain a pre-determined temperature during a regeneration event this DTC will fail, and the regeneration event aborts.

Conditions for Running the DTC
    • The engine control system is in an active regeneration.
    • DTC P244C runs continuously when the above condition is met.

Conditions for Setting the DTC
    • The ECM determines that the EGT sensor 1 is less than 75°C (167°F) of a calibrated threshold, during an active regeneration event.
    • The condition exists for greater than 5 minutes.

Action Taken When the DTC Sets
    • DTC P244C is a Type A DTC.
    • Regeneration will be inhibited.

Conditions for Clearing the DTC

DTC P244C is a Type A DTC.

Diagnostic Aids
    • The use of 500 ppm sulfur, non-road diesel fuel containing red dye, or the continuous use of non ultra low sulfur fuel may be a possible contributor to the degradation of metals in the DOC. A degraded DOC will not light off, and properly maintain the necessary heat required to completely regenerate the particulate filter.
    • If EGT sensor 1 (before the DPF) is slow to respond to exhaust gas temperature changes, or sticks in range, this DTC may set.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation Reference

Diesel Particulate Filter (DPF) System Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

    Important: Perform the Repair Verification after completing the Circuit/System Testing.

  1. Verify that DTCs P003A, P0047, P0048, P0087, P0101, P0201-P0208, P02A1, P02A5, P02A9, P02AD, P02B1, P02B5, P02B9, P02E0, P02E7-P02E9, P029D, P0300-P0308, P0402, P046C, P0420, P0545, P0546, P2032, P2033, P2269 are not set.
    2. ⇒If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
  2. Verify that exhaust leaks do not exist before the DOC. Refer to Exhaust Leakage .

Circuit/System Testing

Important: Perform the Repair Verification after completing the Circuit/System Testing.

  1. Inspect the DOC for any of the following abnormal conditions:
    2. • Physical damage or alterations
    • Internal rattles caused by a damaged catalyst substrate
    • Internal restrictions--Refer to Restricted Exhaust .
         ⇒ If a condition is found, replace the DOC.
  2. Inspect the exhaust system for the following conditions:
    3. • Restrictions--Refer to Restricted Exhaust .
    • Exhaust leaks before DPF
    • Physical damage or alterations
         ⇒If a condition is found, repair the exhaust system as necessary.
  3. Inspect for the following conditions, which may cause a DOC to degrade:
    4. • An engine misfire--Refer to Fuel Injector Balance Test with Tech 2 .
    • Engine oil or coolant consumption
    • Leaking fuel injectors
    • A fuel that does not meet the ultra low sulfur requirements, red dye fuel, or off road diesel fuel
    • Contaminated fuel--Refer to Contaminants-in-Fuel Diagnosis .
         ⇒If a condition is found, repair as necessary, then replace the DOC.
  4. If all inspections and tests are normal, replace the DOC.

Repair Instructions
    •  Catalytic Converter Replacement
    •  Diesel Particulate Filter (DPF) Service Regeneration

Repair Verification
  1. Install any components or connectors that have been removed or replaced during diagnosis.
  2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
  3. Clear the DTCs.
  4. Turn OFF the ignition for 60 seconds.
  5. Duplicate the Conditions for Running the DTC and use the freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
  6. To avoid the customer's return to the service department, perform the Diesel Particulate Filter (DPF) Service Regeneration .