B1370

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.

CAUTION:
Never measure resistance of BPT directly, Current of measuring device may cause unexpected BPT deploy.

DTC Description

The SRSCM sets DTC B1370 if there is a short to power in PBPT harness.
*In this case, SRSCM checks if there's any fault in circuit by sending current for a while.

DTC Detecting Condition






Specification






Diagnostic Circuit Diagram






Monitor Scantool Data

1. Ignition "OFF", connect scantool.
2. Ignition "ON"& Engine "OFF", select "Current Data" mode.
3. Monitor the "Pretensioner front-Passenger resistance" parameter on the Scantool.

Specification :
0.9Ohms< Resistance of Pretensioner front-Passenger< 6.6Ohms

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






Fig.1) Normal Data

4. Is parameter displayed within specifications?






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?






Squib Circuit Inspection

1. Ignition "OFF".
2. Disconnect (-) terminal cable from battery and wait for 1 minutes or more.
3. Disconnect PBPT module and connect the dummy (0957A-38200) and dummy adapter (0957A-2G000) to main harness connector.

NOTE:
If dummy and dummy adaptor are not able to be prepared, use a known-good PBPT or 2Ohms 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.
6. Is DTC present problem ?






Main harness Circuit Inspection

1. Ignition "OFF".
2. Disconnect the battery (-) terminal cable from the battery and wait at least one minutes.
3. Disconnect PBPT connector and SRSCM main harness connector.
4. Connect the battery (-) terminal cable to the battery and Ignition "ON" & Engine "OFF".
5. Measure voltage between terminal "Low" or "High" of the PBPT harness connector and chassis ground.

Specification :approx. 0V

6. Is the measured voltage within specifications?






Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTC)" mode.
2. Using a scan tool, clear the DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTC present ?