B1907
SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1905/74-B1908/74: Short in Front Pretensioner Squib LH Circuit
B1908/74 - Short to B+ in Front Pretensioner Squib LH Circuit
DESCRIPTION
The front pretensioner squib LH circuit consists of the airbag ECU assembly and front seat outer belt assembly LH.
The airbag ECU assembly uses this circuit to deploy the seat belt pretensioner when deployment conditions are met.
These DTCs are stored when a malfunction is detected in the front pretensioner squib LH circuit.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Service Precautions.
HINT
* Perform the simulation method by selecting check mode (Signal Check) using the Techstream Check Mode Procedure.
* After selecting check mode (Signal Check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city road or rough road How To Proceed With Troubleshooting.
PROCEDURE
1. CHECK CONNECTORS
(a) Turn the power switch off.
(b) Disconnect the cable from the negative (-) auxiliary battery terminal.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.
(c) Check that the connectors are properly connected to the front seat outer belt assembly LH and airbag ECU assembly.
OK:
The connectors are properly connected.
HINT
If the connectors are not connected securely, reconnect the connectors and proceed to the next inspection.
(d) Disconnect the connectors from the front seat outer belt assembly LH and airbag ECU assembly.
(e) Check that the terminals of the connectors are not damaged.
OK:
The terminals are not deformed or damaged.
(f) Check that the floor wire connector (on the front seat outer belt assembly LH side) is not damaged.
OK:
The lock button is not disengaged, and the claw of the lock is not deformed or damaged.
(g) Check that the short spring for the floor wire with the activation prevention mechanism is not deformed or damaged.
OK:
The short spring is not deformed or damaged.
Text in Illustration
NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.
2. CHECK FRONT SEAT OUTER BELT ASSEMBLY LH (FRONT PRETENSIONER SQUIB LH)
(a) Connect the connector to the airbag ECU assembly.
(b) Connect SST (resistance 2.1 Ohms) to connector C.
CAUTION:
Never connect the tester to the front seat outer belt assembly LH (front pretensioner squib LH) for measurement, as this may lead to a serious injury due to pretensioner deployment.
NOTICE:
* Do not forcibly insert SST into the terminals of the connector when connecting it.
* Insert SST straight into the terminals of the connector.
SST : 09843-18061
(c) Connect the cable to the negative (-) auxiliary battery terminal.
(d) Clear the DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the power switch off.
(f) Turn the power switch on (IG), and wait for at least 60 seconds.
(g) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B1905/74, B1906/74, B1907/74 or B1908/74 is not output.
HINT
Codes other than DTCs B1905/74, B1906/74, B1907/74 and B1908/74 may be output at this time, but they are not related to this check.
(h) Turn the power switch off.
(i) Disconnect the cable from the negative (-) auxiliary battery terminal.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.
(j) Disconnect SST from connector C.
Text in Illustration
NG -- CHECK FLOOR WIRE
OK -- REPLACE FRONT SEAT OUTER BELT ASSEMBLY LH Removal
3. CHECK FLOOR WIRE
(a) Disconnect the floor wire from the airbag ECU assembly.
(b) Check for a short to B+ in the circuit.
(1) Connect the cable to the negative (-) auxiliary battery terminal.
(2) Turn the power switch on (IG).
(3) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
(4) Turn the power switch off.
(5) Disconnect the cable from the negative (-) auxiliary battery terminal.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.
(c) Check for an open in the circuit.
(1) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(d) Check for a short to ground in the circuit.
(1) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(e) Check for a short in the circuit.
(1) Release the activation prevention mechanism built into connector B Diagnosis System.
(2) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(3) Restore the released activation prevention mechanism of connector B to the original condition.
Text in Illustration
NG -- REPLACE FLOOR WIRE
OK -- Continue to next step.
4. CHECK DTC
(a) Connect the connectors to the front seat outer belt assembly LH and airbag ECU assembly.
(b) Connect the cable to the negative (-) auxiliary battery terminal.
(c) Clear the DTCs stored in memory Reading and Clearing Diagnostic Trouble Codes.
(d) Turn the power switch off.
(e) Turn the power switch on (IG), and wait for at least 60 seconds.
(f) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B1905/74, B1906/74, B1907/74 or B1908/74 is not output.
HINT
Codes other than DTCs B1905/74, B1906/74, B1907/74 and B1908/74 may be output at this time, but they are not related to this check.
Text in Illustration
NG -- REPLACE AIRBAG ECU ASSEMBLY Removal
OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting