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DTC B1453: Curtain Air bag Module (LH) (Squib) System (Shorted to Squib Circuit Power Supply)
 
 


cautionIf DTC B1453 is set in the SRS-ECU, always diagnose the CAN main bus line.
 
 
CIRCUIT OPERATION
  • The SRS-ECU judges how severe a collision is by detecting signals from the side impact sensors installed on the lower side of the center pillar. If the impact is over a predetermined level, the SRS-ECU sends an ignition signal. At this time, if the side collision safing G-sensor is on, the SRS air bag will inflate.
  • The ignition signal is input to the curtain air bag module (LH) to inflate the curtain air bag.
 
 
DTC SET CONDITIONS
This DTC is set if there is abnormal resistance between the input terminals of the curtain air bag module (LH) (squib).
 
 
TROUBLESHOOTING HITS
  • Damaged wiring harnesses or connectors
  • Short to the power supply in the curtain air bag module (LH) (squib) harness
  • Malfunction of the SRS-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect the scan tool ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC 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 Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
 
STEP 3. Check SRS-ECU connector C-125, curtain air bag module (LH) connector D-17.
(1) Disconnect the negative battery terminal.
(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 disconnecting the C-125 SRS-ECU connector, connect it again.
(3) After disconnecting the D-17 harness side connector, connect the connector again. For the D-17 connector disconnection, use the flat-tipped screwdriver to pull out the harness side connector locking button. After releasing the lock, disconnect the connector.
(4) Connect the negative battery terminal.
(5) After erasing the diagnostic trouble code memory, check the diagnostic trouble code again.
(6) Disconnect the negative battery terminal.
Is DTC B1453 set?
Go to Step 4.
Intermittent Malfunction (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 4. Voltage measurement at the C-125 SRS-ECU connector.
(1) Disconnect the negative battery terminal.
(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, and disconnect the C-125 SRS-ECU connector.

(3)
dangerTo release C-125 SRS-ECU wiring harness side connector short spring in the following operations, disconnect D-17 air bag module connector in advance, and keep the squib circuit shorted.
Use the flat-tipped screwdriver to pull out the locking button of harness side connector. After releasing the lock, disconnect the D-17 harness side connector

(4)
cautionThe short spring may not be released due to the insufficient insertion. Therefore, insert the insulator for 4 mm (0.6 inch) or more.
Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminal 36, 37 and the short spring to release the short spring.
(5) Connect the negative battery terminal.
(6) Ignition switch: ON

(7) Measure the voltage between the C-125 wiring harness side connector terminal No. 36, 37 and body ground.Voltage should measure 1 volt or less.
Is the measured voltage within the specified range?
Go to Step 5.
Repair the wiring harness.
 
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC B1453 set?
Replace SRS-ECU (Refer to ).
Intermittent Malfunction (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).