B1207

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

Air Bag OFF Indicator Drive Circuit (Part 1):

Air Bag OFF Indicator Drive Circuit (Part 2):

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 ignition switch (IG1).
- 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.
- If a failure occurs in the system, the SRS-ECU will stop sending that SRS warning light "OFF" signal, thus causing the combination meter to illuminate the SRS warning light.
- The SRS warning light "OFF" signal is not sent to the combination meter in the cases below,either.Therefore,the combination meter will illuminate the SRS warning light.
- The SRS-ECU connector is disconnected.
- The SRS-ECU is not working normally due to a failure in its power supply lines.
- The wiring harness between the passenger's air bag OFF indicator light and the SRS-ECU is broken.

DTC SET CONDITIONS
This DTC will be set if the passenger's air bag OFF indicator light driving circuit is short to ground. If the vehicle condition returns to normal, DTC B1207 will be automatically erased, and the warning light will go out.

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.






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.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool". Scan Tool Connecting
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 (Refer to Controller area network, Diagnosis).

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 (Refer to general (body and chassis), How to Cope With Intermittent Malfunction).

STEP 3. Using scan tool MB991958, read the diagnostic
trouble code.

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.

1. Turn the ignition switch to the "ON" position.
2. Check if the DTC is set.
3. Turn the ignition switch to the "LOOK (OFF)" position.

Q: Is DTC B1BAA, B2207, B2208, B2209, B220A, B220B, B220C or B220D set?

YES : Carry out the troubleshooting of the occupant classification-ECU or the occupant classification sensor system. (Refer to assembly B1BAA, B2207, B2208, B2209, B220A, B220B, B220C or B220D).

NO : Go to Step 4.

STEP 4. Check the center panel assembly connector C-18.

Q: Is the connector correctly engaged?

YES : Go to Step 5.

NO : Engage the connector correctly. Then go to Step 10.

STEP 5. Measure the voltage at center panel assembly connector C-18.

1. Disconnect center panel assembly connector C-18.




2. Measure the voltage between C-18 harness side connector terminal 8 and body ground.Voltage should measure approximately 12 volt.

Q: Is the check result satisfactory?

YES : Go to Step 7.

NO : Go to Step 6.

STEP 6. Check the harness for short circuit between ETACS-ECU connector C-317 (terminal No.5) and center panel assembly connector C-18 (terminal No.8).

Q: Are the harness wires between center panel assembly connector C-18 (terminal No.8) and the ETACS-ECU connector C-317 (terminal No.5) in good condition?

YES : Go to Step 7.

NO : Repair the harness wires. Then go to Step 10.

STEP 7. Check SRS-ECU connector C-122.

Q: Is the connector correctly engaged?

YES : Go to Step 8.

NO : Engage the connector correctly. Then go to Step 10.

STEP 8. Check the harness for short circuit between center panel assembly connector C-18 (terminal No.11) and SRS-ECU connector C-122 (terminal No.18).

Q: Are the harness wires between SRS-ECU connector C-122 (terminal No.18) and the center panel assembly connector C-18 (terminal No.11) in good condition?

YES : Go to Step 9.

NO : Repair the harness wires. Then go to Step 10.

STEP 9. Check the center panel assembly.

1. Disconnect the negative battery terminal.
2. Disconnected the SRS-ECU connector C-122, and measure at the wiring harness side.




3. 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-122 SRS-ECU connector.
4. Connect the negative battery terminal.
5. Turn the ignition switch to the "ON" position.




6. Connect terminal No.18 to ground.

Q: Does the indicator light illuminate?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1207 set, replace the SRS-ECU. Go to Step 10.

NO : Replace the center panel assembly (Refer to Interior, Instrument Panel Assembly). Go to Step 10.

STEP 10. 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 : Return to Step 1.

NO : The procedure is complete.