P2401
DTC P2400-P2402
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 Descriptors
DTC P2400
- Evaporative Emission (EVAP) System Leak Detection Pump Control Circuit
DTC P2401
- Evaporative Emission (EVAP) System Leak Detection Pump Control Circuit Low Voltage
DTC P2402
- Evaporative Emission (EVAP) System Leak Detection Pump Control Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The evaporative emission (EVAP) system uses an EVAP leak detection pump to test for system leaks. The EVAP leak detection pump assembly consists of the following components:
* EVAP leak detection pump with reference orifice
* EVAP leak detection pump switching valve
* EVAP leak detection pump pressure sensor
The ECM commands the EVAP leak detection pump control circuit through an internal switch called a driver. The ECM monitors the commanded and actual status of the driver. If the ECM detects they do not match a DTC sets.
Conditions for Running the DTC
* The vehicle is ON.
* P2400, P2401 and P2402 run continuously when the above conditions are met.
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 for a minimum of 5 s.
Action Taken When the DTC Sets
DTCs P2400, P2401 and P2402 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P2400, P2401 and P2402 are Type B DTCs.
Diagnostic Aids
* The EVAP leak detection pump is very quiet. You might feel it running rather than hear it.
* The devices have to be in their commanded state.
* Where multiple DTCs set look for a common root cause like battery feeds, grounds, splices, etc.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Evaporative Emission Control System Description Description and Operation
Hybrid Modes of Operation Description Hybrid Modes of Operation Description
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
Note: This EVAP leak detection pump is very quiet. You might feel it running rather than hear it.
1. Vehicle in Service Mode, observe the EVAP leak detection pump output control parameters with a scan tool.
* EVAP Leak Detection Pump Output Circuit High Voltage Test Status
* EVAP Leak Detection Pump Output Circuit Open Test Status
* EVAP Leak Detection Pump Output Circuit Low Voltage Test Status
Each parameter should display OK or Not Run.
2. 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
1. Vehicle OFF, disconnect the harness connector at the Q63 evaporative emission system leak detection pump.
2. Vehicle in Service Mode, verify that a test lamp illuminates between the battery circuit terminal 3 and ground.
• If the test lamp does not illuminate, test the battery circuit for a short to ground or an open/high resistance. If the circuit tests normal and the battery circuit fuse is open, test all components connected to the battery circuit and replace as necessary.
3. Test for 2.5-3.5 V between the control circuit terminal 4 and ground.
• If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
• If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Command the EVAP leak detection pump ON and OFF with a scan tool. The DMM should transition from 2.5-3.5 V when commanded OFF, to less than 0.2 V when commanded ON.
• If not the specified values, replace the K20 ECM.
5. If all circuits test normal, test or replace the Q63 evaporative emission system leak detection pump.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Evaporative Emission System Vacuum Leak Detection Pump Replacement Service and Repair
* Control Module References Programming and Relearning for ECM replacement, setup, and programming