P20CD
DTC P10CD, P10CE, P20CD, or P20CE
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.
DTC Descriptor
DTC P10CD
- Exhaust Aftertreatment Fuel Injector High Control Circuit Low Voltage
DTC P10CE
- Exhaust Aftertreatment Fuel Injector High Control Circuit High Voltage
DTC P20CD
- Exhaust Aftertreatment Fuel Injector Control Circuit Low Voltage
DTC P20CE
- Exhaust Aftertreatment Fuel Injector Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The engine control module (ECM) supplies power and ground to the high and low control circuits of the indirect fuel injector. When the ECM detects a fault on either of the indirect fuel injector circuits it sets a DTC.
Conditions for Running the DTC
* Battery Voltage is greater than 11 V.
* Engine speed is greater than 600 RPM.
Conditions for Setting the DTC
* The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.
* The condition exists for more than 3 s.
Action Taken When the DTC Sets
DTC P10CC, P20CB, P20CD and P20CE are Type B DTCs.
Conditions for Clearing the DTC
DTC P10CC, P20CB, P20CD and P20CE are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Exhaust Aftertreatment System Description (Emission Control Systems)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
1. Engine running, observe the following control circuit parameters with a scan tool:
* Exh Aftrtmnt Fuel Inj High Ctrl Ckt Short Volts Test Status
* Exh Aftrtmnt Fuel Inj High Ctrl Ckt Short Gnd Test Status
* Exh Aftrtmnt Fuel Inj Ctrl Ckt Shorted Test Status
* Exh Aftrtmnt Fuel Inj Ctrl Ckt Open Test Status
Each parameter should display OK or Not Run.
2. Ignition ON, command the Exh. Aftertreatment Fuel Injector to 50 %. Verify an audible click at the Q57 indirect fuel injector.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Note: Poor fuel supply could over heat and damage the HC injector.
1. Ignition OFF, disconnect the harness connector at the Q57 indirect fuel injector.
2. Ignition ON, command the Exh. Aftertreatment Fuel Injector to 90% with a scan tool, verify a test lamp flashes ON and OFF between the Hydrocarbon Injector High Control circuit terminal 2 and ground.
• If the test lamp remains illuminated, test the Hydrocarbon Injector High Control circuit for a short to B+. If the circuit tests normal, replace the K20 engine control module.
• If the test lamp does not flash ON and OFF test the Hydrocarbon Injector High Control circuit for an open/high resistance or short to ground, If the circuit tests normal, replace the K20 engine control module.
3. Command the Exh. Aftertreatment Fuel Injector to 90 % with a scan tool, verify a test lamp flashes ON and OFF between the Hydrocarbon Injector High Control circuit terminal 2 and the Hydrocarbon Injector Low Control circuit terminal 1.
• If the test lamp flashes ON and OFF, test or replace the Q57 indirect fuel injector.
• If the test lamp does not flash ON and OFF test the Hydrocarbon Injector Low Control circuit for an open/high resistance or short to B+, If the circuit tests normal, replace the K20 engine control module.
Component Testing
1. Ignition OFF, disconnect the harness connector at the Q57 indirect fuel injector.
2. Test for 12-13 ohm between the control terminal 1 and the control terminal 2 of the Q57 indirect fuel injector.
• If not within the specified range, replace the Q57 indirect fuel injector.
3. Test for infinite resistance between each terminal and the Q57 indirect fuel injector housing/case.
• If not the specified value, replace the Q57 indirect fuel injector.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Indirect Fuel Injector Replacement (Indirect Fuel Injector Replacement)
* Control Module References (Programming and Relearning)for ECM replacement, programming, and setup.