DTC P1473

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5913421 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P1473 Particulate Matter Sensor Supply Voltage Circuit High Circuit/System Description For an overview of the component/system, refer to: Exhaust Aftertreatment System Description

Component	Description
B136 Exhaust Particulate Matter Sensor	The sensor measures the particulate matter in the form of soot in the exhaust. The actual sensor surface is only a few square millimeters in size. On the surface there are 2 microscopic comb-shaped electrodes with intertwined tines (electrical traces) to have the longest possible route of transitions from one to the other electrode. Soot is conductive, therefore when soot deposits between the electrodes, electrical current can flow from one electrode to the other. The more soot deposits between the electrodes, the lower the resistance. To measure the resistance, voltage is applied to the electrodes. The voltage also generates an electrical field that attracts the soot. If the sensor surface is saturated, the sensor is electrically heated to burn off the soot. The sensor sends measured values and state of health information via serial data to the ECM and the reductant control module.
K20 Engine Control Module	The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.

Component

Description

B136 Exhaust Particulate Matter Sensor

The sensor measures the particulate matter in the form of soot in the exhaust. The actual sensor surface is only a few square millimeters in size. On the surface there are 2 microscopic comb-shaped electrodes with intertwined tines (electrical traces) to have the longest possible route of transitions from one to the other electrode. Soot is conductive, therefore when soot deposits between the electrodes, electrical current can flow from one electrode to the other. The more soot deposits between the electrodes, the lower the resistance. To measure the resistance, voltage is applied to the electrodes. The voltage also generates an electrical field that attracts the soot. If the sensor surface is saturated, the sensor is electrically heated to burn off the soot. The sensor sends measured values and state of health information via serial data to the ECM and the reductant control module.

K20 Engine Control Module

The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.

Conditions for Running the DTC P1437 No other DTCs related to the concerned component are set. Ignition On Time = For greater than 3 s Ignition and Start Switch Signal = Greater than 11 V Particulate Matter Sensor Communication Status = On Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC Particulate Matter Sensor = Not within a calibrated range Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type B Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type B Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Master Electrical Component List 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 Circuit/System Verification

Ignition » On / Vehicle » In Service Mode
Verify there are no DTCs set related to the following component/system: – B17 Barometric Pressure Sensor – B34 Engine Coolant Temperature Sensor – B65 Intake Manifold Pressure and Air Temperature Sensor – B75C Multifunction Intake Air Sensor – B131 Exhaust Temperature Sensor ⇒ If a related DTC is set Refer to: Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If a related DTC is not set
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Verify the DTC does not set. ⇒ If the DTC sets Replace the component: B136 Exhaust Particulate Matter Sensor ⇓ If the DTC does not set
All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Exhaust Particulate Matter Sensor Replacement