Code No.B1438: Side Impact Sensor (LH) (Squib) for Power Supply
Circuit
Code No.B1439: Side Impact Sensor (LH) (Squib) for Communication
System
![](../../../img/52/W4X52E006A00ENG.png)
caution |
If diagnosis code B1438 or B1439 is set in the
SRS-ECU, always diagnose the CAN main bus line.
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OPERATION
The side impact sensor includes an analogue G sensor and
CPU, etc. The CPU monitors the analogue G sensor output signal. If the CPU
judges that the side-airbags and curtain air bags should be deployed, it sends
a fire signal to the SRS-ECU to deploy the side-airbags and curtain air bags.
In addition, the CPU diagnoses the internal components of the side impact
sensor. If a malfunction occurs, it requests the SRS-ECU to set a diagnosis
code.
DIAGNOSIS CODE SET CONDITIONS
These diagnosis codes are set if
communication between the side impact sensor (LH) and the SRS-ECU is not
possible or faulty.
PROBABLE CAUSES
- Damaged wiring harnesses or connectors
- Malfunction of the side impact sensor (LH)
- Malfunction of the SRS-ECU
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STEP 1. M.U.T.-III CAN bus diagnostics
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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 line (Refer to GROUP 54F, Diagnosis ).
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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)Ignition: LOCK (OFF) position to ON
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(3)On completion, check that the diagnosis code is not
reset.
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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 the side impact sensor (LH) (M.U.T.-III diagnosis
code).
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(1)Disconnect the negative battery terminal.
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(2)Replace the side impact sensor (LH) with the side impact
sensor (RH).
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(3)Connect the negative battery terminal.
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(4)Erase diagnosis code from memory, and check the diagnosis
code.
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Q.
Is diagnosis code B1428 or B1429 set?
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Replace the side impact sensor
(LH) with a new one (Refer to ). Go to Step 5.
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Go to Step 4.
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STEP 4. Check the harness wires for open circuit or short circuit
between SRS-ECU connector C-120 (terminal No.19 and 20) and side impact
sensor (LH) connector D-18 (terminal No.1 and 2).
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![](../../../img/52/AC311438AE00ENG.png)
![](../../../img/52/AC302579AC00ENG.png)
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Q.
Are the harness wires between SRS-ECU connector C-120 (terminal No.19 and
20) and side impact sensor (LH) connector D-18 (terminal No.1 and 2) in
good condition?
Go to Step 5.
Repair the harness wires between
SRS-ECU connector C-120 (terminal No.19 and 20) and side impact sensor (LH)
connector D-18 (terminal No.1 and 2).
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STEP 5. Check whether the diagnosis code is reset.
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Q.
Is diagnosis code B1438 or B1439 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 Use
Troubleshooting/Inspection Service Points ).
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