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DTC C2022: Vacuum sensor value stuck (VP)
 
 
cautionWhenever ECU is replaced, ensure that the CAN bus lines are normal.
 
 
DTC SET CONDITIONS
When the brake pedal is depressed but the output voltage of the brake booster vacuum sensor does not change, the PHEV-ECU sets DTC C2022.
 
 
 
PROBABLE CAUSES
  • Malfunction of the brake booster vacuum sensor.
  • Damaged harness or connector.
  • Malfunction of the vacuum line.
  • Malfunction of the check valve.
  • Malfunction of the brake booster.
  • Malfunction of the brake electric vacuum pump.
  • Malfunction of the PHEV-ECU.
 
 

 
 
DIAGNOSIS
Required Special Tools
  • MB991223: Wiring harness set
  • MB992006: Extra fine probe
STEP 1. Using scan tool (M.U.T.-IIISE), check whether the other DTC is set.
Check whether another DTC, which is related to the brake vacuum generating system, is set (Refer to ).
Is the DTC set?
Troubleshoot for the relevant DTC.
Go to Step 2.
 
STEP 2. Brake vacuum line check.
Refer to GROUP 35A - On-vehicle Service, Brake Vacuum Line Check .
Is the check result normal?
Go to Step 3.
Repair it.
 
STEP 3. Electric brake vacuum pump check.
Refer to GROUP 35A - On-vehicle Service, Brake Electric Vacuum Pump Check .
Is the check result normal?
Go to Step 4.
Replace the brake electric vacuum pump (Refer to GROUP 35A - Brake Electric Vacuum Pump ).
 
STEP 4. Using scan tool (M.U.T.-IIISE), check the data list. <PHEV-ECU>
Check that the following data list display contents are normal. (Refer to ).
Data list
  • Item No.88: Brake pressure sensor(Physical)
OK: Changes in proportion to the depression stroke.
Is the check result normal?
Go to Step 10.
Go to Step 5.
 
STEP 5. Check at the PHEV-ECU connector and the brake booster vacuum sensor connector.
  1. Connect a voltmeter at the PHEV-ECU connector (terminal VCS1) or the brake booster vacuum sensor (terminal No.2).
  2. Depress the brake pedal, and check that the output voltage fluctuates by 0.2 volt or more with the system activated (the READY indicator illuminated).
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
: Go to Step 6.
: Replace the brake booster vacuum sensor (Refer to GROUP 35A - Master Cylinder Assembly ). Then go to Step 10.
 
STEP 6. Voltage measurement at PHEV-ECU connector (terminals VCSP, VCS1).
(1) Measure the PHEV-ECU connector side by backprobing.
(2) Measure the voltage between the PHEV-ECU connector (terminals VCSP, VCS1) and body ground.
OK: 4.9 - 5.1 volts (Power supply voltage)
Is the check result normal?
Go to Step 8.
Go to Step 7.
 
STEP 7. Check the signal line for open circuit and short to ground circuit (Brake booster vacuum sensor and PHEV-ECU).
  • Brake booster vacuum sensor connector (terminal No.2) and PHEV-ECU connector (terminal VCS1).
  • Brake booster vacuum sensor connector (terminal No.3) and PHEV-ECU connector (terminal VCSP).
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector or wiring harness.
 
STEP 8. Resistance measurement at the PHEV-ECU connector (terminal VCSN).
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Resistance between the PHEV-ECU connector (terminal VCSN) and body ground.
OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 10.
Go to Step 9.
 
STEP 9. Check the signal line for open circuit and short to ground circuit (Brake booster vacuum sensor and PHEV-ECU).
Check the harness between brake booster vacuum sensor connector (terminal No.1) and PHEV-ECU connector (terminal VCSN).
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector or wiring harness.
 
STEP 10. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Recheck the DTC.
noteTo check the DTC again, activate the system (the READY indicator illuminates), and then depress the brake pedal three times strongly within 120 seconds.
(1) Erase the DTC.
(2) Turn off the power supply mode of the electric motor switch.
(3) Depress the brake pedal, and turn on the power supply mode of the electric motor switch (READY operation).
(4) Check the DTC.
Is the DTC set?
Replace the PHEV-ECU (Refer to ).
The procedure is complete.