DTC P0446

DTC P0446	Change over valve (COV) (EVAP system leak detection pump) stuck close
DETECTION CONDITION	The PCM monitors pump load current (EVAP line pressure), while evaporative leak monitor is operating. When the decrease in pump load current is less than the specification after the reference current value has been obtained, the PCM determines change over valve (COV) in EVAP system leak detection pump has a malfunction. Diagnostic support note This is an intermittent monitor (CCM). 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 PCM connector or terminals malfunction Short to power circuit between the EVAP system teak detection pump terminal C and PCM terminal 1V EVAP system leak detection pump (damaged COV) PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 12) HAVE BEEN RECORDED Have the FREEZE FRAME DATA (Mode 12) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 12) on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE BULLETINS AVAILABILITY Verify related Service Bulletins availability. Is any related Service Bulletins available?	Yes	Perform the repair or diagnosis according to the available Service Bulletins. 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 AND TERMINALS Turn the ignition switch off. Disconnect the EVAP system leak detection pump connector. Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 7.
3		No	Go to the next step.
4	INSPECT PCM CONNECTOR AND TERMINALS Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 7.
4		No	Go to the next step.
5	INSPECT COV CONTROL (EVAP SYSTEM LEAK DETECTION PUMP) CIRCUIT FOR SHORT TO POWER SUPPLY EVAP system leak detection pump and PCM connectors are disconnected. Turn the ignition switch to the ON position (Engine off). Measure the voltage between EVAP system leak detection pump connector terminal C (wiring harness-side) and body ground. Is there any voltage?	Yes	Repair or replace the wiring harness for a possible short to power supply, then go to Step 7.
5		No	Go to the next step.
6	INSPECT COV (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 the next step. (See EVAPORATIVE EMISSION (EVAP) SYSTEM LEAK DETECTION PUMP REMOVAL/INSTALLATION ).
6		No	Go to the next step.
7	VERIFY TROUBLESHOOTING OF DTC P0446 COMPLETED Make sure to reconnect all disconnected connectors. Turn the ignition switch to the ON position (Engine off). Clear the DTC from the PCM memory using the M-MDS. Perform the Evaporative Emission (EVAP) System Leak Inspection using the M-MDS. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ). Is the PENDING CODE for this DTC present? NOTE: If the EVAP system test function is not available, perform the following procedure: Perform the Drive Mode 06 (EVAP System Repair Verification Drive Mode). (See OBD-II DRIVE MODE ). Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
7		No	Go to the next step.
8	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 ).
8		No	DTC troubleshooting completed.