Volt

DTC P2418-P2420

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:

The engine control module (ECM) commands the EVAP leak detection pump switching valve to vent or not venting, pumping, position by a switch called a driver. The ECM monitors the commanded state of the driver and the actual state of the control circuit. If they do not match it sets a DTC. The switching valve is located inside the EVAP leak detection pump and is non-serviceable.

P2418, P2419 and P2420 run continuously when the above conditions are met.

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.

DTCs P2418, P2419 and P2420 are Type B DTCs.

DTCs P2418, P2419 and P2420 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Evaporative Emission Control System Description

Hybrid Modes of Operation Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Vehicle in Service Mode, observe the EVAP leak detection pump switching valve parameters with a scan tool.

•	EVAP Leak Detection Pump Switching Valve Output Circuit High Voltage Test Status

•	EVAP Leak Detection Pump Switching Valve Output Circuit Open Test Status

•	EVAP Leak Detection Pump Switching Valve 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.

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 voltage circuit terminal 5 and ground.

⇒	If the test lamp does not illuminate, test the battery voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the battery voltage circuit fuse is open, test all components connected to the battery voltage circuit and replace as necessary.

3. Test for 2.5-3.5 V between the control circuit terminal 1 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 Switching Valve to Venting and Not Venting with a scan tool. The DMM should transition from 2.5-3.5 V when commanded to Venting, to less than 0.2 V when commanded to Not Venting.

⇒	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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.