Code No. C2022: Brake booster vacuum sensor value stuck (Brake electric vacuum pump)



caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be stored. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.

TROUBLE JUDGEMENT


When the brake pedal is depressed but the output voltage of the brake booster vacuum sensor does not change, the PHEV-ECU stores diagnosis code No. C2022.

PROBABLE CAUSES



  • Malfunction of brake booster vacuum sensor
  • Damaged harness or connector
  • Malfunction of vacuum line
  • Malfunction of check valve
  • Malfunction of brake booster
  • Malfunction of brake electric vacuum pump
  • Malfunction of the brake electric vacuum pump main relay
  • Malfunction of PHEV-ECU

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnostics


Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. Check whether the diagnosis code is stored again.


Recheck if the diagnosis code is stored.
(1)Erase the diagnosis code.
(2)Turn on the power supply mode of the electric motor switch.
(3)Check if the diagnosis code is stored.

Q. Is the diagnosis code stored?

Go to Step 3.
The procedure is complete.

STEP 3. M.U.T.-III other system diagnosis code


Check whether another diagnosis code, which is related to the brake vacuum generating system, is stored. (Refer to ).

Q. Is the diagnosis code stored?

Troubleshoot for the relevant diagnosis code.
Go to Step 4.

STEP 4. Brake vacuum line check


Refer to GROUP 35A - On-vehicle Service - Brake Vacuum Line Check .

Q. Is the check result normal?

Go to Step 5.
Repair it.

STEP 5. Electric brake vacuum pump check


Refer to GROUP 35A - On-vehicle Service - Brake Electric Vacuum Pump Check .

Q. Is the check result normal?

Go to Step 6.
Replace the brake electric vacuum pump. (Refer to GROUP 35A - Brake Electric Vacuum Pump )

STEP 6. M.U.T.-III data list


Check that the following data list display contents are normal. (Refer to ).
Data list
  • Item 88: Brake pressure sensor (Physical)
OK: Changes in proportion to the depression stroke.

Q. Is the check result normal?

Go to Step 12.
Go to Step 7.

STEP 7. Check at the PHEV-ECU connector and the brake booster vacuum sensor connector.



  1. Connect a voltmeter at the PHEV-ECU (VCS1 terminal) or the brake booster vacuum sensor (terminal No. 2).
  2. Depress the brake pedal, and check that the output voltage fluctuates by 0.2 V or more with the system activated (the READY indicator illuminated).

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
NO (PHEV-ECU connector fails) : Go to Step 8.
NO (Brake booster vacuum sensor connector is defective) : Replace the brake booster vacuum sensor. (Refer to GROUP 35A - Master Cylinder Assembly <LHD> or <RHD>). Then go to Step 16.

STEP 8. Voltage measurement at PHEV-ECU (VCSP, VCS1 terminal) connector terminal.


(1)Measure the PHEV-ECU connector side by backprobing.
(2)Measure the voltage between the PHEV-ECU (VCSP, VCS1 terminals) connector and body earth.
OK: 5V (Power supply voltage)

Q. Is the check result normal?

Go to Step 10.
Go to Step 9.

STEP 9. Check the signal line for open and short circuit (Brake booster vacuum sensor and PHEV-ECU).



  • Brake booster vacuum sensor connector terminal No.2 and PHEV-ECU (VCS1 terminal) connector.
  • Brake booster vacuum sensor connector terminal No.3 and PHEV-ECU (VCSP terminal) connector.

Q. 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. Resistance measurement at the PHEV-ECU (VCSN terminal) connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Resistance between the PHEV-ECU (VCSN terminal) connector and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 16.
Go to Step 11.

STEP 11. Check the signal line for open and short circuit (Brake booster vacuum sensor and PHEV-ECU).



  • Brake booster vacuum sensor connector terminal No.1 and PHEV-ECU (VCSN terminal) connector.

Q. 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 12. Brake electric vacuum pump main relay check


Refer to GROUP 35A - On-vehicle Service - Relay Check .

Q. Is the check result normal?

Go to Step 13.
Replace the brake electric vacuum pump main relay.

STEP 13. Voltage measurement at PHEV-ECU (VCSP, VCS1 terminal) connector terminal.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between the PHEV-ECU (VPSR terminal) connector and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 16.
Go to Step 14.

STEP 14. Check the power supply line for open and short circuit (IGCT control relay and electric vacuum pump main relay).



  • IGCT control relay and electric vacuum pump main relay connector terminal No. 3.

Q. Is the check result normal?

Go to Step 15.
Repair the connector or wiring harness.

STEP 15. Check the power supply line for open and short circuit (electric vacuum pump main relay and PHEV-ECU).



  • Electric vacuum pump main relay connector terminal No.1. and PHEV-ECU (VPSR terminal) connector.

Q. 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 16. Check whether the diagnosis code is stored again.


Recheck if the diagnosis code is stored.
note To check the diagnosis code again, activate the system (the READY indicator illuminates), and then depress the brake pedal three times strongly within 120 seconds.
(1)Erase the diagnosis code.
(2)Turn on the power supply mode of the electric motor switch.
(3)Check if the diagnosis code is stored.

Q. Is the diagnosis code stored?

Replace the PHEV-ECU (Refer to ).
The procedure is complete.