DTC P2401

DTC P2401	EVAP system leak detection pump control circuit low
DETECTION CONDITION	The PCM monitors the pump load current (EVAP line pressure) when the evaporative leak monitor is operating. If the pump load current is less than the specification, the PCM determines that the EVAP system leak detection pump control circuit voltage is low. Diagnostic support note This is an intermittent monitor (EVAP system). The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle. FREEZE FRAME DATA (Mode 2/Mode 12) is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	EVAP system leak detection pump connector or terminals malfunction Short to ground or open circuit in EVAP system leak detection pump power supply circuit Short to ground in wiring harness between main relay terminal C and EVAP system leak detection pump terminal A EVAP system leak detection pump related fuse malfunction Open circuit in wiring harness between main relay terminal C and EVAP system teak detection pump terminal A Short to ground in wiring harness between EVAP system leak detection pump terminal D and PCM terminal 1U EVAP system leak detection pump malfunction PCM connector or terminals malfunction Open circuit in wiring harness between EVAP system leak detection pump terminal D and PCM terminal 1U PCM malfunction

EVAP system leak detection pump control circuit low

DETECTION CONDITION

The PCM monitors the pump load current (EVAP line pressure) when the evaporative leak monitor is operating. If the pump load current is less than the specification, the PCM determines that the EVAP system leak detection pump control circuit voltage is low.

Diagnostic support note

This is an intermittent monitor (EVAP system).
The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
FREEZE FRAME DATA (Mode 2/Mode 12) is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

EVAP system leak detection pump connector or terminals malfunction
Short to ground or open circuit in EVAP system leak detection pump power supply circuit
- Short to ground in wiring harness between main relay terminal C and EVAP system leak detection pump terminal A
- EVAP system leak detection pump related fuse malfunction
- Open circuit in wiring harness between main relay terminal C and EVAP system teak detection pump terminal A
Short to ground in wiring harness between EVAP system leak detection pump terminal D and PCM terminal 1U
EVAP system leak detection pump malfunction
PCM connector or terminals malfunction
Open circuit in wiring harness between EVAP system leak detection pump terminal D and PCM terminal 1U
PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 12) AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS (EVAP system related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT EVAP SYSTEM LEAK DETECTION PUMP CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the EVAP system leak detection pump connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 9.
3		No	Go to the next step.
4	INSPECT EVAP SYSTEM LEAK DETECTION PUMP POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT EVAP system leak detection pump connector is disconnected. Turn the ignition switch to the ON position (engine off). Measure the voltage between EVAP system leak detection pump terminal A (wiring harness-side) and body ground. Is the voltage B+ ?	Yes	Go to the next step.
4		No	Inspect the EVAP system leak detection pump related fuse. If the fuse is melt: Repair or replace the wiring harness for a possible short to ground. Replace the fuse. If the fuse is deterioration: Replace the fuse. If the fuse is normal: Repair or replace the wiring harness for a possible open circuit. Go to Step 9.
5	INSPECT EVAP SYSTEM LEAK DETECTION PUMP CONTROL CIRCUIT FOR SHORT TO GROUND EVAP system leak detection pump connector is disconnected. Turn the ignition switch off. Inspect for continuity between EVAP system leak detection pump terminal D (wiring harness-side) and body ground. Is there continuity?	Yes	If the short to ground circuit could be detected: Repair or replace the wiring harness for a possible short to ground. If the short to ground circuit could not be detected: Replace the PCM (short to ground in the PCM internal circuit). (See PCM REMOVAL/INSTALLATION Go to Step 9.
5		No	Go to the next step.
6	INSPECT EVAP SYSTEM LEAK DETECTION PUMP Inspect the EVAP system leak detection pump. (See EVAPORATIVE EMISSION (EVAP) SYSTEM LEAK DETECTION PUMP INSPECTION ). Is there any malfunction?	Yes	Replace the EVAP system leak detection pump, then go to Step 9. EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM REMOVAL/INSTALLATION ).
6		No	Go to the next step.
7	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 9.
7		No	Go to the next step.
8	INSPECT EVAP SYSTEM LEAK DETECTION PUMP CONTROL CIRCUIT FOR OPEN CIRCUIT EVAP system leak detection pump and PCM connectors are disconnected. Turn the ignition switch off. Inspect for continuity between EVAP system leak detection pump terminal D (wiring harness-side) and PCM terminal 1U (wiring harness-side). Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9	VERIFY TROUBLESHOOTING OF DTC P2401 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE ). Perform the evaporative system test using the M-MDS. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ). Is the same DTC present? NOTE: If the evaporative system test function is not available, perform the following procedure. Perform the DRIVE MODE 6 (EVAP System Repair Verification Drive Mode). (See OBD-II DRIVE MODE ]) Is the PENDING CODE the same as the DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE ". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
10		No	DTC troubleshooting completed.