B0079

Code

Generic B — Body

Driver Seat Belt Pretensioner B Deployment Control

Brand: Generic

Type: B — Body

Views: UK: 20 EN: 66 RU: 44

AI status

Completed

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Completed 100%

Page language: EN

Causes

Open or high-resistance circuit in driver pretensioner (B) squib wiring
Short to ground or short to battery in the pretensioner circuit
Corroded, loose or damaged connector at the pretensioner or SRS module
Pretensioner already deployed and not replaced or replaced with incorrect part
Faulty pretensioner squib (internal short or open)
Airbag/SRS control module fault or internal driver for the pretensioner channel

Symptoms

SRS/airbag warning lamp illuminated or flashing at key-on
Stored DTC B0079 (and possibly other SRS codes) in airbag control module
Seat belt pretensioner will not be available for deployment in an actual crash (reduced restraint function)
Visible evidence of previous deployment (torn covers, burns) in some cases
Possible disabling of related safety systems until fault cleared

What to check

Use a capable diagnostic scanner to read all SRS codes and freeze-frame data; record and note additional SRS/occupant sensing codes
Verify SRS warning lamp behavior at key-on and note any lamp flash counts
Visually inspect driver seat belt pretensioner assembly, connectors, and wiring harness for damage, burns, corrosion, or repair evidence
Inspect SRS fuses, grounds, and module connectors for security and corrosion
With vehicle power removed and following manufacturer safety wait, measure pretensioner squib resistance and compare to manufacturer specification
Perform continuity check between pretensioner connector and SRS module; check for shorts to ground or battery

Signal parameters

Pretensioner squib resistance (typical intact squib): low ohms — commonly around 1–5 ohms (use manufacturer spec)
Open-circuit: infinite/OL indicates broken/disconnected squib or open wiring
Short condition: measured resistance approaching 0 ohms or unexpected continuity to ground/battery indicates a short
SRS module reports: deployment detected flag, resistance out-of-range, or circuit short/open status
SRS/airbag warning lamp status: ON/steady or flashing indicates active SRS faults

Diagnostic algorithm

Safety first: disable the SRS system per manufacturer procedure (disconnect battery negative and wait the specified time—commonly 90 seconds or manufacturer-specified delay) before any connector or squib resistance checks. Use appropriate PPE when working on SRS components.
Scan and record all SRS codes and freeze-frame data. Note related codes that may point to wiring or occupant-sensor issues.
Visually inspect driver pretensioner assembly, harness runs, connectors, and seat interfaces for damage, corrosion, signs of heat/burn (deployment), or poor repairs.
Check SRS fuses, module grounds, and connector retention. Repair any obvious issues and re-scan.
With SRS power removed and following the safety wait, measure pretensioner squib resistance at the connector. Compare to OEM spec. An open reading suggests an open circuit; a very low/near-zero reading suggests a short.
Perform continuity checks from the pretensioner connector back to the airbag control module connector pin for that channel. Check for unintended continuity to ground or battery voltage.
Perform a wiggle test on the wiring and connectors while monitoring the circuit for intermittent changes (with power removed for resistance testing; powered checks of SRS circuits should follow strict manufacturer procedures).
If wiring or connector faults are found, repair or replace affected sections. If squib resistance is out of spec and wiring is good, replace the pretensioner with the correct OEM part.
If wiring and pretensioner are within spec, consider SRS control module fault — verify module power/ground and communication. Replace or reprogram module only after confirming module-level failure per OEM diagnostics.
After repair or component replacement, clear codes with a scan tool and perform an SRS system check. Confirm SRS lamp extinguishes and no related codes return.
Any replacement of SRS components (pretensioner or control module) may require module resets, seat/occupant sensor recalibration, or module programming — follow OEM procedures or refer to a qualified SRS technician.

Likely causes

Open/failed squib (broken wire or connector)
Connector corrosion or poor crimp at the pretensioner or module
Pretensioner already deployed and was not replaced
Short to ground on the squib wiring harness

Fault status

⚠️ Status

Fault detected in driver seat belt pretensioner B deployment control circuit — possible open, short, deployed/incorrect part, connector or control module issue. SRS warning lamp illuminated.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1.5 - 3.0 hours