B1207

DTC B1207: Passenger's Air Bag OFF Indicator Light (Short Circuit between Circuit Terminal)













CAUTION:
If DTC B1207 is set in the SRS-ECU, always diagnose the CAN main bus line.

CIRCUIT OPERATION

- Power for the passenger's air bag OFF indicator light is supplied from the fusible link (34).

- The passenger's air bag OFF indicator light illuminates when the ignition switch is turned to the "ON" position and goes out after approximately seven seconds if there is not a malfunction in the SRS system. In the following situations, the indicator will stay on to show that the passenger's (front) air bag is not operational.
- The occupant is determined to be less than 66 lbs (30 kg) by the occupant classification-ECU.
- The front passenger's seat is not occupied.

DTC SET CONDITIONS

This DTC will be set if the passenger's air bag OFF indicator light driving circuit is short to ground.

TROUBLESHOOTING HINTS

- Damaged wiring harnesses or connectors
- Malfunction of the SRS-ECU
- Malfunction of the passenger's air bag OFF indicator light

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN Communication System)

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.





(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958. Refer to "How to connect the scan tool Reading and Clearing Diagnostic Trouble Codes."
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the CAN bus line found to be normal?

YES Go to Step 2.

NO Repair the CAN bus line CAN Bus Diagnostics Chart).

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

(1)Erase the DTC.

(2)Turn the ignition switch to the "ON" position.

(3)Check if the DTC is set.

(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?

YES Go to Step 3.
NO There is an intermittent malfunction such as poor engaged connector(s) or open circuit How to Cope With Intermittent Malfunctions).
STEP 3. Check the passenger's air bag OFF indicator light.

(1)It is checked whether the passenger's air bag OFF indicator light is normal
(Refer to Passenger's Air Bag Off Indicator Light Check).

Q. Is the check result normal?

YES Go to Step 4.
NO Replace instrument center panel Instrument Panel Assembly Removal and Installation).
STEP 4. Resistance measurement at the C-37 SRS-ECU connector.

(1)Disconnect the negative battery terminal.





(2)While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-37 SRS-ECU connector.
(3)Disconnect the instrument center panel connector C-124.





(4)Take the measurements below at the SRS-ECU harness side connector. It should be open circuit.

- Continuity between terminal No.18 and body ground

Q. Is it open circuit?

YES Go to Step 5.

NO Repair the wiring harnesses between the C-37 SRS-ECU connector terminal No. 18 and the C-124 instrument center panel connector terminal No.11. Then go to Step 6

STEP 5. Resistance measurement at the C-37 SRS-ECU connector.

(1)Disconnect the negative battery terminal.





(2)While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-37 SRS-ECU connector.





(3)
CAUTION:
Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

Check for continuity between the C-37 SRS-ECU harness side connector terminal No.18 and body ground.
It should be open circuit.

Q. Is it open circuit?

YES Go to Step 6.

NO Replace SRS-ECU (Refer to Service and Repair).

STEP 6. Recheck for diagnostic trouble code.

Check again if the DTC is set.

(1)Erase the DTC.

(2)Turn the ignition switch to the "ON" position.

(3)Check if the DTC is set.

(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is DTC B1207 set?

YES Replace SRS-ECU (Refer to Service and Repair).
NO There is an intermittent malfunction such as poor engaged connector(s) or open circuit How to Cope With Intermittent Malfunctions).