K34 is the RPO code for electronic cruise control. It is a plain code with no ambiguity across forty years of documents, and the reason to look it up is almost never curiosity — it is because you are trying to work out whether your truck was built with cruise, or whether someone added it later.
That distinction decides which parts you buy.
Where K34 is documented
| Year | How GM described it | Source |
|---|---|---|
| 1984 | “Cruise control, automatic, electronic” | GM option master |
| 2007 | “Electronic cruise control” | 2007 Chevrolet Silverado Classic Truck Restoration Kit |
| 2021 | “Cruise Control — Electronic with set and resume speed” | GM Upfitter special-service specification guides |
| 2022–2023 | “Electronic with set and resume speed, steering wheel-mounted” | GM Upfitter guides (2022 also appears in a secondary transcription) |
| 2025–2026 | “Cruise control” | GM Fleet order guides; 2026 police specification guides; GM Canada eOGLD |
Twenty-two GM-sourced records. GMT400, GMT900 and K2XX sit in a documentation gap for us — K34 was offered on all of them, we simply have not yet sourced a GM document that lists it for those years. We also hold unverified 2019 entries for T1XX and K2XX that did not meet our sourcing bar.
Why the code matters more than the buttons
You can see whether a truck has cruise buttons by looking at the steering wheel. What you cannot see is whether the rest of the system is there. On older trucks, factory cruise means:
- A cruise module or servo, and its vacuum plumbing on pre-drive-by-wire engines
- The correct clockspring and steering-wheel wiring
- A brake switch with the extra contact set that cancels cruise
- The right pin population in the body harness connectors
A truck with K34 has all of that from the factory. A truck without it has a wheel someone swapped in, and the buttons do nothing until the rest follows. That is the single most common cruise-control disappointment on an older GM truck.
K34 and the steering wheel codes
These get tangled together because they all live on the same part.
| Code | What it covers |
|---|---|
| K34 | The cruise control system — module, switch, wiring |
| UK3 | Steering wheel mounted controls — the buttons themselves |
| NK5 | The standard urethane wheel |
| NP5 | The leather-wrapped wheel |
From 2022 GM’s own K34 description says “steering wheel-mounted”, which folds the two together on modern trucks. On older ones they are genuinely separate line items.
If your cruise stopped working
On GMT800-era trucks the usual culprit is not the cruise system at all — it is the brake light switch, which carries the cancel circuit. Cruise that will not set, brake lights stuck on, and a shifter locked in park all trace back to the same cheap part. We covered it in the GMT800 brake light switch fix.
How to check your truck
- Find the RPO label — glove box lid, console lid, or under the spare.
- Decode K34 for your model year.
- If K34 is absent but the wheel has buttons, the wheel was changed. Check the clockspring and brake switch before buying a module.
Sources
- 2007 Chevrolet Silverado Classic Truck Restoration Kit, GM Heritage Archive
- 2021–2023 GM Upfitter special-service and police package specification guides
- 2025–2026 GM Fleet order guides; 2026 police specification guides; GM Canada eOGLD
- GM VPPS option master, November 2002
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