DTC P2401: EVAP System Leak Detection Pump Control Circuit Low [11/2021 - ]: Procedure

1. Disconnect the connector from ECM.
2. Turn the ignition switch to ON.
3. Measure the voltage between ECM connector and engine ground.

   Connector & terminal

   B1-25 (MPMP) - Engine ground

   Is the voltage 10 V or higher?

   Result	Proceed to
   Yes	A
   No	B

Result: 

B 

See step  3

Result: 

A 

See step  2

1. Check for poor contact of ECM connector.

   Is there poor contact of ECM connector?

   Result	Proceed to
   Yes (Repair the poor contact of ECM connector.)	A
   No (Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.) HINT:  In this case, temporary open or short circuit of harness or temporary poor contact of connector may be the cause.	B

Result: 

A 

REPAIR CONNECTOR 

Result: 

B 

PERFORM SIMULATION TEST 

1. Disconnect the connector from the canister pump module.
2. Measure the voltage between the canister pump module connector and chassis ground.

   Connector & terminal

   M23-3 - Chassis ground

   Is the voltage 10 V or higher?

   Result	Proceed to
   Yes	A
   No (Repair the following item.) Open circuit in harness between No. 1 engine room relay block and No. 1 junction block assembly and the canister pump module connector Blown out of fuse Poor contact of J/C Poor contact of coupling connector	B

Result: 

B 

REPAIR RELATED PARTS 

Result: 

A 

See step  4

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the canister pump module.
4. Measure the resistance between canister pump module and chassis ground.

   Connector & terminal

   M23-4 - Chassis ground

   Is the resistance 1 MΩ or more?

   Result	Proceed to
   Yes	A
   No (Repair the short circuit to ground in harness between ECM connector and canister pump module connector.)	B

Result: 

B 

REPAIR HARNESS OR CONNECTOR 

Result: 

A 

See step  5

1. Measure the resistance of harness between ECM connector and the canister pump module connector.

   Connector & terminal

   B1-25 (MPMP) - M23-4

   Is the resistance less than 1 Ω?

   Result	Proceed to
   Yes	A
   No (Repair the following item.) Open circuit in harness between ECM connector and the canister pump module connector Poor contact of coupling connector	B

Result: 

B 

REPAIR RELATED PARTS 

Result: 

A 

See step  6

1. Check the vacuum pump of the canister pump module.

   Refer to INSPECTION [11/2021 - ]

   Is the check result OK?

   Result	Proceed to
   Yes (Repair the poor contact in the canister pump module connector.)	A
   No (Replace the canister pump module)	B

Result: 

A 

REPAIR CONNECTOR 

Result: 

B 

CHECK CANISTER PUMP MODULE 

Refer to REMOVAL [11/2021 - ]