Code No.B1438
Side impact sensor (LH) communication error Code No.B1439 Side impact sensor (LH) communication
impossible
caution
If the diagnosis code B1438
or B1439 is set to SRS-ECU, be sure to diagnose the CAN bus line.
OPERATION
The side impact sensor transmits acceleration data to the SRS-ECU. The SRS-ECU then determines.
if the side and/or curtain air bags should be inflated, and then sends an ignition
signal. The side impact sensor also diagnoses itself, and sends a diagnosis code to the SRS-ECU
if a problem occurs.
DIAGNOSIS CODE SET CONDITIONS
The diagnosis code is set if the communication between the left side impact sensor and
SRS-ECU is abnormal (No. B1438), or impossible (No. B1439).
PROBABLE CAUSES
Damaged wiring harnesses or connectors
Malfunction of the side impact sensor (LH)
Malfunction of the SRS-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the 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, Diagnosis ).
STEP 2. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition: "LOCK" (OFF) position to "ON"
(3)On completion, check that the diagnosis code is not reset.
Q.
Is the diagnosis code set?
Go to Step 3.
There is an intermittent malfunction such as poor engaged connector(s) or open
circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
STEP 3. Check the side impact sensor (LH).
(1)Disconnect the negative battery terminal.
(2)Alternate the side impact sensor (LH) and the side impact sensor (RH), and then
install the alternated sensor.
(3)Connect the negative battery terminal.
(4)Erase diagnosis code from memory, and check the diagnosis code.
Q.
Is diagnosis code B1438 or B1439 set?
Replace the side impact sensor (LH) with a new one (Refer to ).
Go to Step 5.
Go to Step 4.
STEP 4. Check of short to power supply, short to earth, and open circuit
in SSL+, SSL- line in between SRS-ECU connector and side impact sensor (LH) connector.
Q.
Is the check result normal?
Go to Step 5.
Repair the connectors or harness wires.
STEP 5. Check whether the diagnosis code is reset.
Q.
Is diagnosis code B1438 or B1439 set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).