Recall 12V434 affects 3,864 2007-2010 Mack Cxu and Chu trucks for fog-light wiring shorts. Repair is free at any franchised Mack dealer.
Mack is recalling 3,864 2007-2010 Cxu and Chu trucks equipped with daytime running lights and fog lights because a fog light circuit short can cut out the low beam headlights. If the low beams go out, the driver loses visibility and crash risk increases; the Mack dealer repair will be free once available.
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What's wrong?
The fog light circuit on 2007-2010 Mack Cxu and Chu trucks powers the fog lamps and sits within the same exterior lighting system as the daytime running lights and low beam headlights. The wiring, fuses, and circuit breakers are supposed to carry power to the lamps and protect the circuits from excess current.
On affected trucks, a short in the fog light circuit can interrupt the low beam headlight circuit. That means a fault tied to the fog lights can make the low beam headlights cut out, leaving the truck without its normal forward lighting when those lights are needed.
There is no warning sign before failure. The first sign can be the low beam headlights cutting out while the fog light circuit is active.
Who's affected?
Scope is split between Chu and Cxu trucks from 2007-2010, with fog lights and wiring listed as the affected components.
| 2008 Mack Cxu | Fog lights |
|---|---|
| 2008 Mack Cxu | wiring |
| 2007 Mack Cxu | Fog lights |
| 2007 Mack Cxu | wiring |
| 2010 Mack Chu | Fog lights |
| 2010 Mack Chu | wiring |
| 2007 Mack Chu | Fog lights |
| 2007 Mack Chu | wiring |
| 2009 Mack Cxu | Fog lights |
| 2009 Mack Cxu | wiring |
| 2008 Mack Chu | Fog lights |
| 2008 Mack Chu | wiring |
| 2010 Mack Cxu | Fog lights |
| 2010 Mack Cxu | wiring |
| 2009 Mack Chu | Fog lights |
| 2009 Mack Chu | wiring |
| Units affected | 3,864 |
The year and model narrow the scope, but the VIN decides. Check your VIN to confirm whether your specific truck is included.
What's the safety risk?
Loss of low beam headlights reduces nighttime visibility and increases crash risk. If the lights go out while driving, slow down, pull over safely, and call a Mack dealer. Repair will be free at any franchised Mack dealer once available.
What should I do?
- Check your VIN to confirm your 2007-2010 Mack Cxu or Chu is included in this recall.
- Contact a franchised Mack dealer to ask about the free additional wiring harness repair.
- Schedule the wiring harness installation that protects the fog-light circuit from cutting out the low beam headlights.
- Bring the recall notice if Mack mailed one. If not, reference recall number 12V434 when you call.
- Avoid night driving until the repair is complete, and use extra caution if the low beam headlights cut out.
What happens at the repair
At the dealer, a Mack technician installs an additional wiring harness on the affected CHU and CXU trucks. That harness addresses the fog light circuit short that can shut off the low beam headlight circuit. The dealer repair will be free once available for your VIN. Ask the service desk to confirm the campaign applies before the truck is brought in, since the VIN decides whether this repair is covered under recall 12V434.
Timeline
| September 6, 2012 | NHTSA published the recall |
|---|---|
| November 14, 2012 | Owner notification mailed |
Frequently asked questions
What is recall 12V434?
Recall 12V434 covers 3,864 2007-2010 Mack Cxu and Chu trucks with daytime running lights and fog lights. A short in the fog-light circuit can cut out the low-beam headlights. Mack installs an additional wiring harness for free.
What should I do if my 2007-2010 Mack Cxu or Chu is on this recall?
Check your VIN to confirm your specific truck is included in recall 12V434. If it is, call a franchised Mack dealer to schedule the additional wiring harness installation. Reference recall number 12V434 when you call. The repair is free.
Is the recall repair free?
Yes. Mack installs the additional wiring harness free of charge at a franchised Mack dealer. Federal recall law requires the manufacturer to repair the defect at no cost, and Mack also lists 1-800-866-1177 for owner questions.
What is the safety risk?
The safety risk is loss of low-beam headlights while driving. If the low beams go out, the driver loses forward visibility, increasing crash risk. The free dealer repair adds wiring protection to address the fog-light circuit short.
When did Mack start this recall repair?
Mack started the safety recall repair on November 14, 2012. For an included 2007-2010 Mack Cxu or Chu, contact a franchised Mack dealer and ask for recall 12V434. The dealer repair remains free for included trucks.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/12V434000 |
|---|---|
| Mack customer service | 1-800-866-1177 |
| NHTSA recall # | 12V434 |
| NHTSA recall # (full) | 12V434000 |
Source documents
-
Download Recall Investigation Document (PDF) (PDF) - Download Recall Document (PDF) (PDF)
- Download Recall Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Owner Notice (PDF)
- Download Defect / Noncompliance Notice (PDF) (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on June 2, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →