B1461
DTC B1461: Seat Belt Pre-Tensioner (RH) (Squib) System Fault 2 (Open in the Squib Circuit)Passenger's (Front) Seat Belt Pre-Tensioner (Squib) Circuit Part 1:
Passenger's (Front) Seat Belt Pre-Tensioner (Squib) Circuit Part 2:
CIRCUIT OPERATION
The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU sends an ignition signal. At this time, if the front air bag safing G-sensor is on, the pre-tensioner will deploy.
DTC SET CONDITIONS
This DTC is set if there is abnormal resistance between the input terminals of the passenger's seat belt pre-tensioner (squib).
TROUBLESHOOTING HINTS
- Open circuit in the passenger's seat belt pre-tensioner (squib) circuit
- Improper connector contact
- Malfunction of the SRS-ECU
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A (Vehicles with CAN communication)
- MB991865: Dummy resistor
- MB991884: Resister harness (For Pre-tensioner)
STEP 1. Recheck for diagnostic trouble code.
Check again if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "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 2.
NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to How to Cope with Intermittent Malfunction).
STEP 2. Check the passenger's seat belt pre-tensioner. (Using scan tool MB991958, read the diagnostic trouble code.)
1. Disconnect the negative battery terminal.
2. Disconnect passenger's seat belt pre-tensioner connector D-39. Use a flat-tipped screwdriver to unlock the locking button at the harness side connector by withdrawing it toward you in two stages, and then disconnect the connector.
3. Connect special tool MB991865 to special tool MB991884.
4. Connect special tool MB991884 to the D-39 harness side connector.
5. Connect the negative battery terminal.
6. Erase diagnostic trouble code memory, and then check the diagnostic trouble code.
Q: Is DTC B1461 set?
YES: Go to Step 3.
NO: Replace the passenger's seat belt pre-tensioner. Then go to Step 4.
STEP 3. Check the harness for open circuit between SRS-ECU connector C-114 (terminal No.59 and 60) and the passenger's seat belt pre-tensioner connector D-39 (terminal No.1 and 2).
1. Disconnect SRS-ECU connector C-114 and passenger's seat belt pre-tensioner connector D-39. For connector D-39, use a flat-tipped screwdriver to unlock the locking button at the harness side connector by withdrawing it toward you in two stages, and then disconnect the connector.
2. Connect D-39 harness side connector to special tool MB991884.
CAUTION: Do not insert a test probe into the terminal from its front side directly as the connector contact pressure may be weakened.
3. Check for continuity between the following terminals. It should be less than 2 Ohms.
- SRS-ECU connector C-114 (terminal No.59) and the special tool (terminal No.2)
- SRS-ECU connector C-114 (terminal No6.0) and the special tool (terminal No.1)
Q: Does continuity exist?
YES: Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1461 sets, replace the SRS-ECU. Then go to Step 4.
NO: Replace the harness wires between SRS-ECU connector C-114 passenger's seat belt pre-tensioner connector D-39. Then go to Step 4.
STEP 4. 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 B1461 set?
YES: Return to Step 1.
NO: The procedure is complete.