Cruise control buttons form a resistor ladder on one or two signal lines, each button giving its own voltage window. FCA uses two lines with offset windows – signal 1 is input A, signal 2 input B – and both must report the same button; GM evaluates the ratio to the reference. Any fault locks out cruise control; CARB treats this as emission-neutral, and GM and Ford set these codes without warning lamp. P0589 is the general fault of the second button input B. GM uses it only for one engine variant (LGW): the ratio lies in a gap between valid button windows for over 0.5 s. It is the counterpart of P0564 for input A.
Low severity. Can I keep driving?You can keep driving, but check that the brake lights work: that part is a safety issue.
Symptoms
- Cruise or distance control unavailable
- Cruise control locked out
- No check engine light
Most likely causes
- Increased contact resistance shifting button voltages
- Button block aged or damp
- Clockspring faulty
- Module input
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of P0589 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 5: Speed and idle
- 89: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0589?
You can keep driving, but check that the brake lights work: that part is a safety issue.
What causes code P0589?
The most common causes are: increased contact resistance shifting button voltages; button block aged or damp; clockspring faulty.
Related codes
- P0564Cruise Control Multi-Function Input A Circuit
- P0590Cruise Control Multi-Function Input B Circuit Stuck
- P0591Cruise Control Multi-Function Input B Circuit Range/Performance
- P0592Cruise Control Multi-Function Input B Circuit Low
- P0593Cruise Control Multi-Function Input B Circuit High
- P0585Cruise Control Multi-Function Input A/B Correlation
Sources
- gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
- gsi.ext.gm.com: 19OBDG03B Diagnostics
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.