B1362 Pretensioner Front-Driver Resistance too Low

COMPONENT LOCATION

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GENERAL DESCRIPTION
Seat Belt Pretensioner(hereinafter referred to BPT) is located at both side of center pillar.
BPT tightens seat belt before air bag deploys to protect passenger from bumping against crush pad, steering wheel and front window.
In BPT, there are a ignition circuit and cylinder for rewinding belt.
Cylinder has piston that can rewind seat belt in it.
Gas chamber generates expansive force of gases to push piston in cylinder.
   
 
Never measure resistance of BPT directly, Current of measuring device may cause unexpected BPT depoy.
DTC DESCRIPTION
The SRSCM sets DTC B1362 if the measured resistance value of DBPT circuit is less than the threshold value.
*In this case, SRSCM checks if there’s any fault in circuit by sending current for a while.
DTC DETECTING CONDITION
 
ItemDetecting ConditionPossible cause
DTC Strategy
Check Resistance
1.
Poor connection of connected part.
2.
Poor connection between shorting bar and release pin.
3.
Faulty DBPT.
4.
Faulty SRSCM.
Enable Conditions
Ignition “ON”
Threshold Value
DBPT resistance ≤ 1.6Ω
Diagnostic TimeQualification
More than 2.5s
De-Qualification
More than 5s

 

SPECIFICATION
 
Test ConditionResistance
Ignition ON1.6Ω ≤ Squib resistance ≤ 6.0Ω

 

DIAGNOSTIC CIRCUIT DIAGRAM

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MONITOR SCANTOOL DATA
1.
Ignition “OFF”, connect scantool.
2.
Ignition “ON”& Engine “OFF”, select “Current Data” mode.
3.
Monitor the “Pretensioner front-Driver resistance” parameter on the Scantool.
 1.6Ω< Resistance of Pretensioner front-Driver < 6.0Ω

 

Reference : In a case of an open in the Pretensioner front-Driver circuit : FAIL
In a case of a short to battery in the Pretensioner front-Driver circuit: FAIL
In a case of a short to ground in the Pretensioner front-Driver circuit : FAIL

 

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Fig.1) Normal Data
4.
Is parameter displayed within specifications?
 

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▶ Displaying nothing(no DTC) or DTC with label “H”(historical) shows that Fault is intermittent caused by poor contact in the part’s and/or SRSCM connector or was repaired and SRSCM memory was not cleared.
Thoroughly check shorting bar/shorting bar release pin and connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
▶ Repair or replace as necessary

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▶ Go to “W/Harness Inspection” procedure.

 

TERMINAL AND CONNECTOR INSPECTION
1.
Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2.
Thoroughly check shorting bar/shorting bar release pin and connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3.
Has a problem been found?
 

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▶ Repair as necessary and then go to “Verification of Vehicle Repair” procedure.

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▶ Go to “Squib Circuit Inspection” procedure.
SQUIB CIRCUIT INSPECTION
1.
Ignition “OFF”.
2.
Disconnect (-) terminal cable from battery and wait for 1 minutes or more.
3.
Disconnect DBPT module and connect the dummy and dummy adapter to main harness connector.
   
 
If dummy and dummy adaptor are not able to be prepared, use a known-good DBPT or 2Ω resistor.
4.
Connect (-) terminal cable to battery and Ignition “ON” & Engine “OFF” and wait for 30 seconds or more.
5.
Connect scantool to Data Link Connector(DLC) and clear DTC with scantool and diagnose again.

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6.
Is DTC present problem ?
 

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▶ Go to “Main harness circuit inspection” procedure.

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▶ Substitute a known-good DBPT assembly, and check for proper operation.
If the problem is corrected, replace DBPT 
MAIN HARNESS CIRCUIT INSPECTION
1.
Ignition “OFF”.
2.
Disconnect the battery (-) terminal cable from the battery and wait at least one minutes.
3.
Disconnect DBPT connector and SRSCM main harness connector.
4.
Measure resistance between terminal “Low” and “High” of the DBPT harness connector.
 approx. 1 Ω below

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5.
Is the measured resistance within specifications?
 

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▶ Substitute a known-good SRSCM, and check for proper operation.
If the problem is corrected, replace SRSCM 

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▶ Substitute the SRSCM main harness and check for proper operation.
If the problem is corrected, replace SRSCM main harness 

 

 

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