P145C
DTC P145C or P145D
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 P145C
- Evaporative Emission (EVAP) System Leak Detection Pump Stuck Off
DTC P145D
- Evaporative Emission (EVAP) System Leak Detection Pump Stuck On
Circuit/System Description
This evaporative emissions (EVAP) system is a closed system. This vehicle's internal combustion engine (ICE), which is the consistent source of vacuum for conventional vehicles, only runs at predetermined times for regeneration. Therefore the need for a consistently reliable vacuum source - the EVAP system leak detection pump.
The EVAP leak detection pump assembly consists of three main components - a vacuum pump, a switching valve, and a pressure sensor. These DTC's deal only with the pump operation.
This pump is used for fuel tank pressure (FTP) sensor correlation or leak checking the EVAP system. The engine control module (ECM) has a wake-up timer, which is located in the hybrid powertrain control module 2. It activates the ECM at three calibratable times so that leak detection can occur.
The EVAP leak detection vacuum pump stuck on test is performed by comparing an initial EVAP leak detection pump pressure sensor, absolute, reading to a second reading after the EVAP leak detection pump switching valve transitions from vent to not venting, pump, position for a short period of time. The EVAP leak detection pump switching valve transitions back to vent position after the second EVAP leak detection pump pressure sensor reading. A difference between the two pressure readings indicates the EVAP leak detection vacuum pump is stuck on and sets DTC P145D.
Conditions for Running the DTC
P145C and P145D
Propulsion System Not Active
Note: There are three possible time windows for this test to run. Up to that point and through this time period the propulsion system must not be active. These time windows are: 5.0, 7.0 or 9.5 hours.
* P043E, P043F, P0451, P1458, P145C, P145D, P145E, P2421, P2422 and P2450 are not present.
* Purge valve closed
* Vent solenoid valve closed
* EVAP Leak Detection Pump switching valve vent position
* EVAP Leak Detection Pump vacuum pump ON
* Odometer greater than 15.9 km (9.9 mi)
* Barometric pressure 70-110 kPa (10.15-15.95 PSI)
* Fuel level 10-90%
* Engine coolant temperature less than 40°C
* Intake air temperature 4-45°C
* System voltage greater than 10 V
* Vehicle speed less than 1.6 km/h (1 MPH)
If any of these conditions occur this test is aborted.
* Key up during test
* Refueling request button pressed
* Service bay test active
* Device control exceeds 0.5 seconds
* P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0128, P012B, P012C, P012D, P0222, P0223, P0449, P0452, P0453, P0461, P0462, P0463, P0498, P0499, P0502, P0503, P06E4, P0722, P0723, P1221, P1459, P145A, P2066, P2067, P2068, P2400, P2401, P2402, P2418, P2419, P2420, P2537, P2610, U0073, U0074, U0140, U182D are not present.
Conditions for Setting the DTC
P145C
When the EVAP leak detection pump is commanded ON during the first reference orifice vacuum measurement, if the stabilized EVAP leak detection pump pressure sensor vacuum reading is 100 pa (0.01 PSI) after 6 min, or when the EVAP leak detection pump is commanded ON during the second reference orifice vacuum measurement, if the stabilized EVAP leak detection pump pressure sensor vacuum reading is 100 pa (0.01 PSI) after 30 s the vacuum pump is stuck OFF and the DTC fails.
P145D
The first time in the test sequence when the EVAP leak detection pump is commanded OFF and after the EVAP leak detection pump switching valve transitions from vent to not venting, pump, position. If the difference between an initial EVAP leak detection pump pressure sensor reading and a second EVAP leak detection pump pressure sensor reading is 1 kPa (0.14 PSI) after 8 s or the second time in the test sequence when the EVAP leak detection pump is commanded OFF and the EVAP leak detection pump pressure sensor vacuum reading is greater than 1.18 kPa (0.17 PSI) after 14 s the vacuum pump is stuck ON and the DTC fails.
Action Taken When the DTC Sets
DTCs P145C and P145D are Type B DTCs.
Conditions for Clearing the DTC
DTCs P145C and P145D are Type B DTCs.
Diagnostic Aids
The EVAP leak detection pump is very quiet. You might feel it running rather than hear it.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Description and Operation
Evaporative Emission Control System Description Evaporative Emission Control System Description
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 Control Module References for scan tool information
Circuit/System Verification
* Verify that DTC P145C and P145D are not present.
* 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. Ignition OFF, disconnect the harness connector at the Q63 evaporative emission system leak detection pump assembly.
2. Verify that a test lamp illuminates between the voltage supply circuit terminal 3 and ground.
• If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the Q63 evaporative emission system leak detection pump assembly.
3. Connect a test lamp between the voltage supply circuit terminal 3 and the control circuit terminal 4.
4. Command the EVAP leak detection pump ON and OFF with a scan tool. The test lamp should respond to the command.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
5. If all circuits test normal, replace the Q63 evaporative emission system leak detection pump assembly.
Repair Instructions
* Clear DTCs.
* 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 Control Module References for ECM replacement, setup, and programming