Code No.B1632
Knee air bag module (squib) system (open circuit of squib circuit)
<Vehicles with rear curtain
air bag>
| caution |
- If
diagnosis code B1632 is set in the SRS-ECU, be sure to diagnose the CAN
bus line.
|
|
|
Only when the frontal impact exceeding the
threshold is simultaneously detected (turned
ON) by the front impact sensor as well as by the analogue G-sensor and
safing G-sensor in SRS-ECU,
the electric current is supplied from SRS-ECU to the knee air bag module
(squib).
|
|
|
The code is set when the open circuit occurs to
the SRS-ECU knee air bag module (squib)
circuit.
|
|
|
- Open circuit in the knee air bag module (squib) circuit
- Poor contact of connector
- Malfunction of SRS-ECU
|
|
|
STEP 1. M.U.T.-III CAN bus diagnostics.
|
|
|
Use M.U.T.-III to diagnose the CAN bus
lines.
|
|
|
Q.
Is the check result normal?
|
|
|
 Go to Step 2.
|
|
|
|
|
|
 Repair
the CAN bus line (Refer to GROUP 54C - Troubleshooting  ).
|
|
|
|
|
|
STEP 2. M.U.T.-III diagnosis code.
|
|
|
(1)Connect the negative battery terminal.
|
|
|
(2)After erasing the diagnosis code memory, check the
diagnosis code again.
|
|
|
(3)Disconnect the negative battery terminal.
|
|
|
Q.
Is diagnosis code No. B1632 set?
|
|
|
Go to Step 3.
|
|
|
|
|
|
Intermittent malfunction (Refer to
GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunction).
|
|
|
|
|
|
STEP 3. Diagnosis check by dummy resistor connection.
|
|
|
(1)Check that the negative battery terminal is disconnected.
If the negative battery
terminal is connected, disconnect it.
|
|
(2)Use the flat-tipped screwdriver to pull out
the locking button of wiring harness side
connector, and release the lock.
|
|
(3)Connect the dummy resistor (Special tool:
MB991865) to the resistor harness (Special tool:
MB991884).
(4)Connect the resistor harness (special tool) to right
curtain air bag module connector.
(5)Connect the negative battery
terminal.
(6)After erasing the diagnosis code memory, check the
diagnosis code again.
Q.
Is diagnosis code No. B1632 set?
Go to Step 4.
Replace the knee air bag
module.
|
|
|
STEP 4. Resistance measurement at the SRS-ECU connector and the knee
air bag module connector.
|
|
|
(1)Check that the negative battery terminal is disconnected.
If the negative battery
terminal is connected, disconnect it.
|
|
(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.
After disconnect the SRS-ECU
connector.
|
|
(3)
| danger |
To release the connector short spring in the
following operations,
disconnect this harness side connector, and keep the squib circuit
shorted.
|
Use the flat-tipped screwdriver to pull out the locking button of
wiring harness side
connector, and release the lock.
|
|
(4)
| caution |
The short spring may not be released due to the
insufficient insertion. Therefore, insert
the insulator for 4 mm or more.
|
Insert an insulator (width: 3 mm, thickness: 0.5 mm) such as cable
tie between the KDS+,
KDS- line, and then release the short spring.
(5)
| caution |
Do not insert a probe directly into the terminal of
harness side connector
from the connector front side as the connector contact pressure may be
weakened.
|
Take the measurements below at the SRS-ECU connector and knee air
bag module connector
harness side connectors.
- Continuity KDS- line between the SRS-ECU connector and
the knee air bag module connector.
- Continuity KDS+ line between the SRS-ECU connector and the knee
air bag
module connector.
OK: Continuity (less than 2 Ω)
Q.
Is the check result normal?
Go to Step 5.
Repair the wiring harnesses
KDS+, KDS- line between the knee air bag
module connector and the SRS-ECU connector.
|
|
|
STEP 5. Check whether the diagnosis code is set again.
|
|
|
Q.
Is diagnosis code No. B1632 set?
|
|
|
Replace SRS-ECU.
|
|
|
|
|
|
Intermittent malfunction (Refer to
GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunction).
|
|
|
|