Diagnosis code No.B1722 is stored when the immobilizer-ECU cannot communicate with the ignition key because of defective key ring antenna (antenna wire).
COMMENT ON TROUBLE SYMPTOM
Current trouble
The wiring harness wire or connectors between the immobilizer-ECU and the key ring antenna may have loose, corroded, or damage terminals, or terminals pushed back in the connector, or the key ring antenna (antenna wire) may be defective.
Past trouble
If diagnosis code No.B1722 is stored as a past trouble, it is possible that there were defective wiring harnesses, defective connectors or defective antennas before.
PROBABLE CAUSES
Damaged harness wires and connectors
Malfunction of the key ring antenna (antenna wire)
Malfunction of immobilizer-ECU
DIAGNOSIS PROCEDURE
STEP 1. Check the key reminder switch (ignition key ring antenna)
(1)Disconnect the key reminder switch (ignition key ring antenna) connector C-301.
(2)Take the measurements below at harness-side connector. There should be continuity between terminals 3, 7 and body earth. OK: Continuity exists (2 Ω or less)
Q.
Is the check result satisfactory?
Go to Step 2.
Replace the key reminder switch (ignition key ring antenna), and then go to Step 5 .
STEP 2. Connector check: Immobilizer-ECU connector C-142 and key reminder switch (ignition key ring antenna) connector C-301.
Q.
Is the check result satisfactory?
Go to Step 3.
Repair the connector, and then go to Step 4.
STEP 3. Check the wiring harness between immobilizer-ECU connector C-142 (terminal 7 and 8) and key reminder switch (ignition key ring antenna) connector C-301 (terminal 3 and 7).
Q.
Is the check result normal?
Go to Step 4.
Repair the wiring harness, and then go to Step 4.
STEP 4. Check whether the diagnosis code is reset.
(1)Turn the ignition switch to the "LOCK" (OFF) position once, and then turn it to the ON position again.
(2)Check if diagnosis code No.B1722 is set as a current trouble.
Q.
Is diagnosis code No.B1722 set as a current trouble?
Replace the key reminder switch (ignition key ring antenna), and then go to Step 5.
If diagnosis code No.B1722 is set as a past trouble, erase the diagnosis code that is set as a past trouble, and the diagnosis is complete.
STEP 5. Check whether the diagnosis code is reset.
(1)Turn the ignition switch to the "LOCK" (OFF) position once, and then turn it to the ON position again.
(2)Check if diagnosis code No.B1722 is set as a current trouble.
Q.
Is diagnosis code No.B1722 set as a current trouble?
Replace the immobilizer-ECU and register the ID codes. (Refer to .) After registering the ID codes, return to Step 1.
If diagnosis code No.B1722 is set as a past trouble, erase the diagnosis code that is set as a past trouble, and the diagnosis is complete.