B1207
DTC B1207: Passenger's Air Bag OFF Indicator Light (Short Circuit between Circuit Terminal)Air Bag OFF Indicator Light Drive Circuit (Part 1):
Air Bag OFF Indicator Light 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 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.
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.
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". How To Connect The Scan Tool (M.U.T.-III)
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.
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.
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. Passenger Air Bag Off Indicator Light Check
Q: Is the check result normal?
YES: Go to Step 4.
NO: Replace instrument center panel.
STEP 4. Resistance measurement at the C-122 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-122 SRS-ECU connector.
3. Disconnect the instrument center panel connector C-18.
4. Check for continuity between the C-122 harness side connector terminal No.18 and body ground. It should be open circuit.
Q: Is it open circuit?
YES: Go to Step 5.
NO: Repair the wiring harnesses between the C-122 SRS-ECU connector terminal No. 18 and the C-18 instrument center panel connector No.11. Then go to Step 6
STEP 5. Resistance measurement at the C-18 instrument center panel 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-122 SRS-ECU connector.
CAUTION: Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
3. Check for continuity between the C-18 harness side connector terminal No.11 and body ground.
It should be open circuit.
Q: Is it open circuit?
YES: Go to Step 6.
NO: Replace instrument center panel.
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.
NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit.