Code No. B1551:
SRS warning lamp circuit malfunction (Lamp does not Illuminate)
OPERATION
The auxiliary battery power supply is supplied from the electric motor switch to the SRS
warning lamp. When SRS-ECU operates normally, the SRS warning lamp is illuminated for 6 to 8 seconds
after the electric motor switch is turned to the "ON" position, and extinguished afterward.
TROUBLE JUDGEMENT
This diagnosis code will be set if the SRS warning lamp driving circuit is short to earth.
PROBABLE CAUSES
Damaged wiring harnesses of connectors
Malfunction of the SRS-ECU
Malfunction of the combination meter
DIAGNOSIS PROCEDURE
STEP 1. Voltage measurement at the B-101 combination meter
connector.
(1)Check that the negative auxiliary battery terminal is disconnected. If the negative
auxiliary battery terminal is connected, disconnect it.
(2)Disconnect the B-101 combination meter connector.
(3)Connect the negative auxiliary battery terminal.
(4)Electric motor switch to the "ON" position.
(5)
caution
Do not insert a test probe into the
terminal from its front side directly as the connector contact pressure may be weakened.
Take the measurements below at the B-101 combination meter connector.
Voltage between terminal No. 2 and body earth
OK: 9 V or more
(6)Disconnect the negative auxiliary battery terminal.
Q.
Is the check result normal?
Go to Step 3
Go to Step 2
STEP 2. Check the harness for open circuit between electric motor
switch and B-101 combination meter connector.
note
Prior to the wiring harness inspection, check junction block connector B-302 and B-305,
and repair if necessary.
The SRS warning lamp circuit inspection for open circuit
Q.
Is the check result normal?
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
Repair the harness wires. Then go to Step 5.
STEP 3. Check the harness for short circuit between the B-101 combination
meter connector (terminal No.15) and B-112 SRS-ECU connector (terminal No.39).
note
Prior to the wiring harness inspection, check B-120 intermediate connector and earth connector
B-25 and B-11 <LHD>, and repair if necessary.
The SRS-ECU signal lines inspection for short to earth
Q.
Is the check result normal?
Go to Step 4
Repair the harness wires.Then go to Step 5
STEP 4. Check the SRS warning lamp.
(1)Check that the negative auxiliary battery terminal is disconnected. If the negative
auxiliary battery terminal is connected, disconnect it.
(2)Disconnected the B-112 SRS-ECU connector.
(3)Connect the negative auxiliary battery terminal.
(4)Electric motor switch to the "ON" position.
Q.
Does the SRS warning lamp illuminate?
Go to Step 5
Replace the combination meter (Refer to GROUP 54A, Combination
Meter ).
STEP 5. Check whether the diagnosis code is reset.
Q.
Is the diagnosis code set?
Replace the SRS-ECU (Refer to ).
An intermittent malfunction is suspected (Refer to GROUP 00, How to Cope with
Intermittent Malfunction ).
)
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Go to Step 3
Go to Step 2
).