Code No.B1440:
Curtain air bag module (RH) (squib) system (short-circuited between terminals of the squib circuit)
| caution |
If diagnosis code B1440 is set in the SRS-ECU, always diagnose
the CAN bus lines.
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OPERATION
The SRS-ECU judges how severe a collision is by detecting signals from the side impact
sensors and the side air bag safing G-sensor. If the impact is over a predetermined level, the
SRS-ECU outputs an ignition signal. At this time, if the side air bag safing G-sensor is on,
the curtain air bag module will deploy.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if one curtain air bag module squib (RH) wire shorted to the
other.
PROBABLE CAUSES
- Improper engaged connector or defective short spring*
- Short circuit between the curtain air bag module (RH) (squib) circuit terminals
- Damaged connector(s)
- Malfunction of the SRS-ECU
| note |
*: The squib circuit connectors integrate a "short" spring (which prevents the
air bag from deploying unintentionally due to static electricity by shorting the positive wire
to the earth wire in the squib circuit when the connectors are disconnected). Therefore, if
connector B-109 or C-06 is damaged or improperly engaged, the short spring may not be released
when the connector is connected.
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STEP 1. M.U.T.-III CAN bus diagnostics.
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| warning |
Since the radiator fan rotates during CAN bus line diagnostics,
make sure that no one is servicing the engine compartment before diagnosing the CAN bus line.
Since the CAN communication stops when diagnosing the CAN bus line, the ETACS-ECU detects the
time-out of the engine-ECU, and activates the radiator fan to prevent overheating as fail-safe.
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Use the M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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 Go to Step 2.
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 Repair the CAN bus lines (Refer to GROUP 54C, Troubleshooting - Can Bus
Diagnosis Table  ).
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STEP 2. Check whether the diagnosis code is reset.
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Check again if the diagnosis code is set.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch to the "ON" position.
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(3)Check if the diagnosis code is set.
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(4)Turn the ignition switch to the "LOCK" (OFF) position.
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Q.
Is the diagnosis code set?
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Go to Step 3.
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There is an intermittent malfunction such as poor engaged connector(s) or open
circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
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STEP 3. Check SRS-ECU connector B-109 and curtain air bag module (RH)
connector C-06 (M.U.T.-III diagnosis code).
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(1)Disconnect the negative battery terminal.
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(2)Disconnect connectors B-109 and C-06, and then reconnect them. For connector C-06, use
a flat-tipped screwdriver to pull out forward and unlock the locking button of the harness side
connector, and then disconnect the connector.
(3)Connector the negative battery terminal.
(4)Erase the diagnosis code memory, and check the diagnosis code.
Q.
Is diagnosis code B1440 set?
Go to Step 4.
The procedure is complete. It is assumed that diagnosis code B1440 set as connector
B-109 or C-06 was engaged improperly.
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STEP 4. Check the curtain air bag module (RH) (M.U.T.-III diagnosis
code).
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(1)Disconnect the negative battery terminal.
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(2)Use a flat-tipped screwdriver to pull out forward and unlock the locking button of the
harness side connector, and then disconnect curtain air bag module (RH) connector C-06.
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(3)Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991884).
(4)Connect special tool resistor harness (MB991884) to the C-06 harness side connector.
(5)Connect the negative battery terminal.
(6)Erase diagnosis code memory, and then check the diagnosis code.
Q.
Is diagnosis code B1440 set?
Go to Step 5.
Replace the curtain air bag module (RH) (Refer to ).
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STEP 5. Resistance measurement at the SRS-ECU connector B-109
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(1)Disconnect the negative battery terminal.
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(2)Disconnect SRS-ECU connector B-109.
| danger |
To prevent the air bag from deploying unintentionally, disconnect the curtain air bag
module (RH) connector C-06 to short the squib circuit.
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(3)Use a flat-tipped screwdriver to pull out forward and unlock the locking button of the
harness side connector, and then disconnect curtain air bag module (RH) connector C-06.
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(4)
| caution |
Insert an insulator such as a cable tie to a depth of 4mm or more, otherwise the short
bar will not be released.
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Insert a cable tie [3 mm wide, 0.5 mm thick] between terminals 32 and
the short spring to release the short spring.
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(5)Resistance measurement between B-109 harness side connector terminals 7 and 8.
OK: Open circuit
Q.
Is the check result normal?
Go to Step 6.
Repair the harness wire between SRS-ECU connector B-109 (terminal No.7 and 8)
and curtain air bag module (RH) connector C-06 (terminal No.2 and 1).
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STEP 6. Check whether the diagnosis code is reset.
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Q.
Is diagnosis code B1440 set?
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Replace the SRS-ECU (Refer to ).
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An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
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