B0042 on 2006-2013 Chevrolet Impala: Airbag Light Causes and Fixes

What's Unique About the 2006-2013 Chevrolet IMPALA

The 9th generation Impala, along with many other GM vehicles from this era, is subject to a Technical Service Bulletin (TSB #08-09-41-002H) for intermittent airbag lights. The bulletin highlights that the small plastic Connector Position Assurance (CPA) retainers on airbag connectors become brittle and fail, leading to poor connections and triggering codes like B0042. This makes a simple connector issue a far more likely cause than a major component failure.

Diagnostic Flowchart

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Symptoms You May Notice

• Airbag warning light is continuously illuminated on the dashboard.
• "Service Airbag" message displayed on the Driver Information Center (DIC).

Most Likely Causes

1. Broken or Loose Airbag Connector Position Assurance (CPA) Retainer 🔴 High Probability As documented in GM TSB #08-09-41-002H, the plastic CPA retainers on airbag connectors for this vehicle generation become brittle and break, causing an intermittent or poor connection. This is the most common cause for B0042 on this platform.
   How to confirm: After disconnecting the battery and waiting, access the driver's airbag module. Inspect the yellow connector for a broken or missing orange or black plastic CPA clip. The clip may fall out in pieces upon disconnection.
   Typical fix: Replace the Connector Position Assurance (CPA) retainer. This is a small, inexpensive plastic part that secures the electrical connector. Ensure the connector is fully seated before locking the new retainer in place.
   Est. part cost: $5-$15
2. Failed Clock Spring 🟡 Medium Probability The clock spring's internal ribbon cables flex with every turn of the steering wheel and can wear out or break over time, causing an open or short in the driver airbag circuit. This is a common wear item on many vehicles, including the Impala.
   How to confirm: A technician can test the resistance of the clock spring circuits using a multimeter while rotating the steering wheel. An erratic or out-of-spec reading confirms failure. Other symptoms of a failing clock spring can include the horn or steering wheel-mounted controls not working.
   Typical fix: Replace the clock spring assembly located in the steering column. This requires removing the steering wheel. 🎬 Watch: Step-by-step guide to replacing the clock spring and airbag.
   Est. part cost: $40-$210
3. Wiring Harness or Connector Damage ⚪ Low Probability Wiring under the driver's seat or in the steering column can become chafed or damaged over time. A recall was issued for 2009-2010 Impalas for the passenger presence sensor wiring chafing on the seat frame, indicating a potential for similar issues in other SRS circuits. Owners on forums also report success by cleaning and re-seating large yellow connectors under the center console or seats.
   How to confirm: Visually inspect all accessible yellow-loomed airbag wiring for signs of pinching, chafing, or corrosion, particularly at the connectors under the seats and in the steering column.
   Typical fix: Repair the damaged section of the wiring harness and ensure all connectors are clean, secure, and protected with dielectric grease.
   Est. part cost: $10-$50

Rare But Worth Checking

• Faulty Sensing and Diagnostic Module (SDM): The airbag control module itself can fail internally, but this should only be considered after all wiring, connectors, and the clock spring have been thoroughly tested and ruled out. A hard fault can also be stored after a collision, requiring the module to be reset or replaced even if airbags did not deploy.
• Faulty Driver Airbag Module: An internal short within the driver's airbag inflator assembly (squib) can cause this code. This is uncommon and requires replacement of the entire airbag unit. This should be the last component to be suspected.

Diagnosis Steps

1. SAFETY FIRST: Disconnect the negative battery terminal and wait at least 15-30 minutes for the system's backup power to discharge before proceeding.
2. Scan the SRS module with a capable OBD-II scanner to confirm B0042 is the active code and check for any other related codes.
3. Remove the driver's airbag from the steering wheel (typically by releasing clips through small holes on the side/back of the wheel using a screwdriver or small punch).
4. Carefully inspect the yellow electrical connector and its orange or black Connector Position Assurance (CPA) retainer. This is the most likely point of failure per TSB 08-09-41-002H. Look for cracks, brittleness, or a loose fit.
5. If the CPA retainer is broken or loose, replace it. A common OEM part number for this retainer is GM #88988974. Ensure the connector is fully seated before locking the new retainer in place.
6. If the connector and CPA are intact, inspect the terminals for corrosion or damage. If they look good, the next step is to test the clock spring.
7. If the clock spring is suspected, it should be tested for proper resistance by a professional following service manual procedures. Replacement is a common repair and often the next logical step if the CPA is not the cause.
8. If the clock spring tests good, inspect the wiring harness from the clock spring to the SDM for any signs of damage, paying close attention to connectors under the seats and center console.
9. If all wiring and components test good, the fault may lie with the SDM itself, which would require professional diagnosis and likely replacement/reprogramming.
🎬 Watch: How to remove and reinstall the airbag control module.

Parts You'll Likely Need

• Connector Position Assurance (CPA) Retainer (OEM #88988974) — This small plastic clip is the most common failure point leading to code B0042, as identified in GM Technical Service Bulletin #08-09-41-002H.
  Trusted brands: ACDelco, Dorman
  OEM price range: $5-$15
  Aftermarket price range: $5-$10
• Clock Spring (OEM #19258035) — This is the second most likely cause if the connector retainer is not the issue. It contains the wiring for the driver's airbag that fails from repeated turning of the steering wheel.
  Trusted brands: ACDelco, Standard Motor Products, Dorman (p/n 525-026)
  OEM price range: $100-$150
  Aftermarket price range: $40-$210

Related Codes That Often Appear With This One

• B0044 — B0044 is for the 'Driver Frontal Deployment Loop Open'. Both B0042 and B0044 relate to the driver's airbag circuit and can be caused by the same faulty connectors or clock spring, with the specific code depending on whether the fault is a short (low resistance) or an open circuit.

Technical Service Bulletins (TSBs) & Recalls

• 08-09-41-002H: Addresses intermittent airbag lights caused by faulty Connector Position Assurance (CPA) retainers, and lists B0042 as one of the affected codes. This TSB covers a huge range of GM vehicles from this era, including the 2006-2013 Impala.

Platform-Specific Known Issues

• A widespread issue with brittle airbag connector clips (CPA retainers) is documented in TSB #08-09-41-002H, making it the primary suspect for this code on the 2006-2013 Impala.
• A user on ChevroletForum.com described their intermittent 'Service Air Bag' light, a classic symptom of a failing CPA retainer or clock spring, highlighting how common connection-related issues are.
• Another forum user on Car Talk Community detailed their struggle with an intermittent airbag light, having tried cleaning connectors under the seats and replacing front sensors without success, pointing towards a more elusive cause like the clock spring or a wiring fault.

Mechanic-Grade Diagnostic Values

• Driver Frontal Deployment Loop Stage 2 Resistance — expected: Typically 1.5 - 3.5 Ohms (based on general SRS specifications).. Failure: Code B0042 sets when resistance is less than 1.3 ohms for 500 milliseconds.
• Driver Frontal Deployment Loop Stage 1 or 2 Resistance (for related open circuit codes B0026/B0044) — expected: Typically 1.5 - 3.5 Ohms.. Failure: Code B0044 sets when resistance is greater than 4.8 ohms for 500 milliseconds.
• Example of a known-good GM airbag loop resistance (from a different seat circuit) — expected: 1.74 – 3.41 ohms.. Failure: Readings outside this range indicate a potential fault in the circuit being tested.

Hidden / Shadow Codes Worth Checking

• Symptom Byte: GM systems often append a two-character 'symptom byte' to a primary DTC (e.g., B14DC 1B) to provide more specific details about the fault, such as 'high resistance' or 'open circuit'. While a specific byte for B0042 was not found in searches, a technician should look for one. (see via A professional GM-specific scan tool like a Tech 2 or GDS2 is required to view symptom bytes.)

Scan Tool Commands That Help

• GM Tech 2 / GDS2: SIR Data Display: Deployment Loop Resistance — This function allows a technician to view the live resistance value of the driver's airbag deployment loop. It is critical for diagnosing intermittent faults by monitoring the resistance while turning the steering wheel (to test the clock spring) or wiggling connectors.
• GM Tech 2 / GDS2: Read/Clear DTCs in SIR Module — Used to confirm the B0042 code is active and to clear it after a repair has been performed. The airbag light will not turn off on its own; the code must be cleared from the SIR (airbag) module.

Wiring & Ground Locations

• C221 — Behind the driver's side hinge pillar trim panel (kick panel area).. This IP harness connector is a known point of high resistance for driver's side airbag codes on similar GM platforms and should be inspected for corrosion or poor pin fitment.
• G201 — Behind the left side of the dashboard, on the left side of the brake pedal bracket.. This is a primary instrument panel ground point. A poor ground here could potentially cause erratic behavior in various modules and sensors in the driver's area, including the SIR system.
• G301 — At the base of the driver's side 'B' pillar.. The Sensing and Diagnostic Module (SDM) is often located in the center of the vehicle, under the console or seats, and may use grounds in this vicinity. A poor ground can cause unpredictable SDM behavior.

Real Owner Repair Stories

• ChevroletForum.com user report (Chevrolet Impala (year not specified, but in 9th gen forum)) — Service Air Bag message and airbag light were on continuously.
  ❌ Tried (didn't work) Owner took it directly to a dealer for diagnosis.
  ✅ What actually fixed it A Chevrolet dealer unplugged a connector, cleaned it with contact cleaner, and reconnected it. The repair cost $100 and resolved the issue, indicating a simple connection fault.
• YouTube video by 'Fix it now' (2008 Chevrolet Impala) — Airbag warning light was on solid.
  ✅ What actually fixed it The owner accessed a large yellow connector under the center console from the rear seat area, disconnected it, sprayed it with electrical cleaner, and reconnected it. This immediately turned off the airbag light upon restart.

"I Checked Everything" — The Actual Cause

• The electrical equivalent of a 'smoke test clean' scenario is common with this code. A technician may test the clock spring and wiring with a multimeter and find that the resistance is within spec while the components are stationary. However, the actual fault is an intermittent short or open that only occurs when the steering wheel is turned or when the vehicle hits a bump. The key is to use a scan tool to monitor the deployment loop resistance live while flexing the wiring harness and turning the steering wheel lock-to-lock to expose the hidden fault.

OEM Part Supersession History

• 88988974 → 88988974 (current) — No supersession found. This part number appears to be stable.
  Heads up: While this part number is consistent, it is always best practice to verify the latest part number with a GM dealer using the vehicle's VIN, as minor running changes can occur.

Model Year Variations Within This Range

• 2012-2013: In 2012, the Impala received a major powertrain update, including the 3.6L LFX V6 engine and a 6-speed automatic transmission. However, the core body structure, interior design, and SRS components like the steering column and airbag modules remained fundamentally the same as the 2006-2011 models. Therefore, the causes and fixes for code B0042, especially the TSB regarding the CPA retainer, apply consistently across the entire 2006-2013 generation.