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DTC P24BE: Switching Valve Control Circuit Low

 
 
 
 
CIRCUIT OPERATION
  • The switching valve power is supplied from the MFI relay.
  • The ECM controls ground switching valve by turning the power transistor in the ECM "ON" and "OFF".
 
 
TECHNICAL DESCRIPTION
  • In response to a signal from the ECM, the switching valve switches the atmospheric side path of the evaporative emission canister to the reference path for the evaporative emission system leak monitor.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • More than 2 seconds have passed since the power supply mode of electric motor switch was ON.
  • 12V starter battery positive voltage is between 10 and 16.5 volts.
Judgment Criterion
  • The supply voltage is 3 volts or lower without the switching valve driving for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Fuel filler lid cannot be opened even when pressing the fuel filler lid opener switch.
  • Indicates "REFUELING SYSTEM SERVICE REQUIRED" on the information screen in the multi-information display.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Switching valve failed.
  • Open or shorted switching valve circuit, harness damage or connector damage.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), check evaporative emission system component test item 3 and 4: Switching Valve.
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) .
(2) Turn on the power supply mode of the electric motor switch.
(3) Check the following items in the evaporative emission system component test. Refer to Evaporative Emission System Component Test Reference Table .
  1. Item 3: Vent Valve Solenoid ON
  2. Item 4: Vent Valve Solenoid OFF
(4) Turn off the power supply mode of the electric motor switch.
Is the solenoid operating properly?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
Go to Step 2.
 
STEP 2. Measure the power supply voltage at evaporative leak check module harness side connector.
(1) Disconnect the evaporative leak check module connector and measure at the harness side.
(2) Turn on the power supply mode of the electric motor switch.
(3) Measure the voltage between terminal COVB and ground.
  • Voltage should be 12V starter battery positive voltage.
(4) Turn off the power supply mode of the electric motor switch.
Is 12V starter battery positive voltage (approximately 12 volts) present?
Go to Step 3.
Repair or replace the connector(s), or check and repair the harness of short to ground and open circuit in COVB line between MFI relay connector and evaporative leak check module connector. Then go to Step 8.
 
STEP 3. Measure the power supply voltage at ECM harness side connector.
(1) Disconnect connector and measure at the harness side.
(2) Short-circuit the terminal C/R of the ECM harness connector to the ground.
(3) Measure the voltage between terminal ECOV and ground.
  • Voltage should be 12V starter battery positive voltage.
(4) Turn off the power supply mode of the electric motor switch.
Is 12V starter battery positive voltage (approximately 12 volts) present?
Go to Step 5.
Go to Step 4.
 
STEP 4. Check of short to ground and open circuit in ECOV line between evaporative leak check module connector and ECM connector.
Is the harness wire in good condition?
Replace the switching valve (integrated in evaporative emission canister). Then go to Step 8.
Repair the connector(s) or wiring harness. Then go to Step 8.
 
STEP 5. Check of harness damage in ECOV line between evaporative leak check module connector and ECM connector.
Is the harness wire in good condition?
Go to Step 6.
Repair the connector(s) or wiring harness. Then go to Step 8.
 
STEP 6. Check of harness damage in COVB line between MFI relay connector and evaporative leak check module connector.
Is the harness wire in good condition?
Go to Step 7.
Repair the connector(s) or wiring harness. Then go to Step 8.
 
STEP 7. Using scan tool (M.U.T.-IIISE), check evaporative emission system component test item 3 and 4: Switching Valve.
(1) Turn on the power supply mode of the electric motor switch.
(2) Check the following items in the evaporative emission system component test. Refer to Evaporative Emission System Component Test Reference Table .
  1. Item 3: Vent Valve Solenoid ON
  2. Item 4: Vent Valve Solenoid OFF
(3) Turn off the power supply mode of the electric motor switch.
Is the solenoid operating properly?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
Replace the ECM (Refer to Removal and Installation ). Then go to Step 8.
 
STEP 8. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P24BE set?
Retry the troubleshooting.
The inspection is complete.