Code
B0074
HUMMER
B — Body
Supplemental Deployment Loop #1 Open
AI status
Completed
Completed
100%
Causes
- Broken or disconnected wiring in the deployment loop
- Corroded or loose connector pins at an airbag module or the SRS control module
- Failed inflator/squib or harness short/open inside the module
- Improperly seated or damaged clockspring (if loop includes steering wheel squib)
- Damage from prior repairs, collision, or water intrusion
- Faulty SRS control module (less common) or internal module connector fault
Symptoms
- SRS/Airbag warning lamp illuminated or flashing on dash
- Possible disablement of one or more airbag deployments (stored codes)
- Diagnostic trouble codes related to deployment loop open
- No other driveability symptoms (electrical fault limited to SRS circuit)
What to check
- Read and record stored SRS codes and freeze-frame data with a capable scan tool
- Confirm battery voltage is stable (12.0–14.5 V) before testing
- Visually inspect airbag-related connectors, harness routing, and for crash damage
- Check for other SRS codes that point to the same circuit or a common connector
- Consult vehicle wiring diagrams to identify components and routing for Deployment Loop #1
Signal parameters
- Open circuit: infinite resistance (OL) measured across the deployment loop
- Typical intact squib resistance: approximately 2–5 Ω (vehicle-specific — verify OEM spec)
- Continuity (closed loop) expected between squib pins and SRS module when connectors present
- With system active, SRS module monitors loop for continuity and short-to-ground/short-to-B+
Diagnostic algorithm
- Safety first: follow OEM SRS safety procedures — disconnect battery negative and wait the recommended time to allow SRS backup capacitors to discharge before touching airbag connectors.
- Retrieve and document all SRS-related codes with an appropriate scan tool; note any related B-codes or U-codes.
- Inspect visually: examine harnesses, connectors, and airbag/pretensioner modules along the wiring diagram route for damage, corrosion, or disconnected plugs.
- Identify components on Deployment Loop #1 from the wiring diagram (which squib(s) and connectors are in that loop).
- With battery disconnected and system disabled, perform continuity/resistance checks: measure resistance across the squib/actuator and between the squib and SRS module connector pins. Compare to OEM spec (typical squib ≈ 2–5 Ω). An open/infinite reading indicates a break.
- If continuity is good at the squib but open at the module connector, backprobe or disconnect harness sections to isolate the open section and repair broken wires or terminals.
- Inspect/repair any damaged connectors or wiring using soldering or proper crimp terminals and weatherproofing. Replace corroded connectors or modules as required.
- If an individual squib shows open internally, replace the affected airbag or pretensioner per OEM instructions.
- After repairs, reconnect battery, clear codes with a scan tool, and perform SRS system self-tests. Verify the SRS lamp extinguishes and no new B0074 or related codes return.
- If wiring and components check good but code persists, consider SRS module connector pins and module internal fault — replacement/programming of the SRS module may be required; consult OEM procedures for module replacement and required programming/initialization.
Likely causes
- Open/failed connector at a nearby airbag or seat-belt pretensioner
- Damaged wiring harness (pinched, chafed, or broken)
- Disconnected or corroded connector at the SRS/SDM module
- Failed squib/actuator in the airbag/pretensioner (internal open)
Fault status
Status
Supplemental Deployment Loop #1 Open — the SRS control module has detected an open circuit in deployment loop 1 (loss of continuity in the airbag/pretensioner circuit).
Repair difficulty: Medium
Diagnostic time: 1-3 hours
Similar codes
Repair manuals
Manual library for HUMMER
138
Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HUMMER
-
HUMMER: 2009
-
HUMMER: 2008
-
HUMMER: 2007
-
HUMMER: 2005
-
HUMMER: 2004
-
HUMMER: 2000
-
HUMMER: 1999
-
HUMMER: 1994
-
HUMMER: 1993
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email