C0281 Code on GMC: Sierra, Acadia, Terrain Fix & Part Numbers
Drashco
C0281 on a GMC means: Brake switch circuit open or shorted — the ABS module lost the brake pedal signal.
Most common fix: Replace the brake light switch. Part: AC Delco D1586H / GM 15861245. Cost: $12–$25. Time: 15–20 minutes.
C0281 is one of the most common ABS/traction-control codes on GMC vehicles — and one of the cheapest to fix. The same part fits every GMC sold between 2005 and 2018: Sierra 1500/2500/3500, Acadia, Terrain, Yukon, Canyon, Savana, and the platform-shared Chevy Silverado, Tahoe, Equinox, and Traverse.
Here's the exact fix with part numbers, tools, and the two traps most DIYers fall into on their first attempt.
In this guide:
What C0281 Means on a GMC
C0281 is a chassis DTC that reads: "Brake Switch Circuit — Open or Shorted." The Electronic Brake Control Module (EBCM) watches the brake light switch to coordinate ABS, traction control, and stability systems. Every time you tap the brake, the switch should close, sending a clean 12V signal. When the contact inside the switch wears out (or shorts internally), the EBCM sees the signal flickering or missing — and logs C0281.
This is the same underlying mechanism that trips C0281 on Chevy Aveo, Cobalt, and Subaru platforms; the difference is which part number fits your GMC. See our master C0281 guide for the platform-wide story.
Which GMC Models Are Affected
Based on NHTSA complaint data and dealer TSBs, these GMC vehicles are the most common C0281 offenders:
| Model | Years | Typical Mileage at Failure |
| Sierra 1500 | 2007–2018 | 85,000–150,000 miles |
| Sierra 2500 / 3500 HD | 2007–2018 | 75,000–130,000 miles |
| Acadia | 2007–2016 | 60,000–110,000 miles |
| Terrain | 2010–2017 | 65,000–120,000 miles |
| Yukon / Yukon XL | 2007–2020 | 80,000–140,000 miles |
| Canyon | 2004–2012 + 2015–2018 | 90,000–160,000 miles |
| Savana 1500/2500/3500 | 2003–2014 | 120,000–200,000 miles (fleet use) |
C0281 is also listed in Spanish-language diagnostic manuals as "codigo c0281 chevrolet — falla del interruptor de luz de freno" — same fault, same fix, just the GMC badge switched for Chevrolet.
Symptoms
- ABS warning light on — always
- Traction Control (TCS) / Stabilitrak light on — usually
- Cruise control will not engage — the cruise module uses the same brake signal to disengage; a dodgy switch means it will not engage either
- Brake lights themselves still work — half the switch contacts are fine; the ABS contact is the one that has failed
- Shifter may lock in Park (on vehicles with brake-shift interlock) — rare but telling
- Automatic transmission may shift harshly on older Sierras because the TCM also watches the brake signal
Exact Part Numbers by GMC Model
Good news: GM uses the same brake light switch across almost every model from 2005 to 2018. One part fits them all.
| Part | AC Delco | GM OE | Fits |
| Brake light switch | D1586H (preferred) | 15861245 / 25801998 | Sierra, Acadia, Terrain, Yukon, Canyon, Savana — all years 2005–2018 |
| Brake light switch harness connector (if clip broken) | — | PT716 | Same models |
Avoid generic no-name knockoffs under $10 — they wear out in 2–3 years and you will be doing this job again. The AC Delco part is under $20 at most parts stores and comes with the same OE spec as what came in your truck.
Step-by-Step Replacement
- Park the vehicle and set the parking brake. No need to disconnect the battery for this job.
- Slide the driver's seat all the way back. You will be on your back looking up at the pedals for about 10 minutes.
- Locate the switch. It is a black plastic cylinder about the size of your thumb, mounted on the brake pedal bracket, directly above the brake pedal arm. You can feel the plunger touching the pedal arm.
- Unclip the wiring harness. Press the release tab on the connector and pull. The clip is on the driver's side of the connector — if you push instead of pull, nothing happens.
- Rotate the switch 45° counterclockwise (a quarter turn). The switch unlocks from its retention collar. Pull it straight out.
- Compare old and new parts. The new AC Delco D1586H should match the old one exactly. If the plunger length looks different, you have got the wrong part number.
- Install the new switch in reverse: push it in with the locking tabs aligned, rotate 45° clockwise until it clicks.
- Plug the harness back in. You will hear the tab click when it is fully seated.
- Test the pedal. With the ignition on (engine off is fine), press the brake pedal. You should see the brake lights in your rear-view, and the dash ABS light should begin to clear after 10–15 seconds of normal operation.
- Clear the stored codes with an OBD-II scanner. Drive a 10-minute cycle. The ABS and Stabilitrak lights should stay off.
2 Traps to Avoid
Trap 1: Mis-adjusted pedal gap
The brake light switch has a self-adjusting plunger. If you push the pedal too hard while installing the switch (or step on the pedal afterward before the switch locks), you can over-compress the plunger. Result: the switch never fully releases at rest, and the brake lights stay on permanently — or the ABS light stays on.
Fix: pull the switch back out, rotate counterclockwise a quarter turn, let the plunger extend fully, then reinstall without pressing the pedal.
Trap 2: Wrong switch from the parts store
Some parts stores will hand you a switch that is similar but from a different GM platform. The mounting looks identical but the plunger length differs by 3–4mm. The symptoms will be: brake lights that stay on, or an ABS light that will not clear.
Fix: bring your old switch to the counter and compare side by side before paying. The AC Delco D1586H has a plunger length of 24mm at rest.
Cost Breakdown
| Approach | Cost | Time |
| DIY with AC Delco part | $18–$25 (switch) | 15–20 minutes |
| Independent shop | $120–$180 (part + 1 hour labor) | Drop-off to pickup ~2 hours |
| GMC dealer | $210–$310 | Half-day appointment |
This is one of the three or four highest-ROI DIY repairs on any GMC. $20 in parts, 20 minutes, and you avoid a $180-plus shop bill. No special tools required.
Frequently Asked Questions
Will the same switch work on my Chevy Silverado or Tahoe?
Yes. GM uses the same AC Delco D1586H brake light switch across every Sierra, Silverado, Yukon, Tahoe, Suburban, Acadia, Traverse, Terrain, and Equinox from 2005 to 2018. If you own a GMC and a Chevy in the same garage, one $20 part covers both.
Can a bad brake light switch cause the transmission to shift harshly?
Yes, on older Sierras and Yukons. The transmission control module uses the brake signal to modify torque converter lockup behavior. A flaky switch can cause the TCM to behave as if you are tapping the brakes randomly, which it interprets as a shift request. Replacing the switch fixes the shift quality as well as the ABS code.
Do I need to reprogram the ABS module after replacing the brake light switch?
No. The brake switch is a simple on/off signal source, not a programmed module. Plug in the new one, clear the codes, and drive. No dealer visit needed.
Why did C0281 come back after I replaced the switch?
Three possibilities, in order of likelihood: (1) the new switch is defective (warranty exchange at the parts store), (2) the pedal gap is mis-adjusted — see Trap 1 above, or (3) the real fault is in the harness connector or the wiring between the switch and the EBCM. A 20-minute multimeter check at the switch connector will tell you which it is.
Is C0281 covered under the GMC powertrain warranty?
No. C0281 is a chassis/ABS code, not a powertrain code. The standard 5-year/60,000-mile powertrain warranty does not cover it. However, if your GMC is still under the 3-year/36,000-mile bumper-to-bumper, the repair is free at a dealer.
The brake lights work fine — why is C0281 thrown?
The brake light switch has multiple contacts inside a single housing. One contact is dedicated to the brake lights (the one you care about when you are being tailgated), and a separate contact sends a signal to the ABS/EBCM module. The brake-light contact is usually fine; the ABS contact is the one that wears out and throws C0281. Same switch, different failure mode.
Codigo C0281 en un GMC — ¿es el mismo problema?
Sí, es exactamente el mismo problema. El código C0281 significa "falla del circuito del interruptor de la luz de freno" y la solución es reemplazar el interruptor. La pieza AC Delco D1586H vale alrededor de $20 USD y la instalación toma 15–20 minutos. Para una guía en español, consulte nuestra guía completa de C0281 en vehículos GM.
