OBD-II Diagnostic Trouble Code
P0590 — Cruise Control Multi-Function Input B Stuck
P0590 means the ECM sees cruise control multi-function input B (often the set/coast or resume/accel function, depending on the manufacturer) stuck in one state for longer than it expects. A stuck input makes the ECM disable cruise so the truck doesn't keep accelerating or coasting on its own.
Severity 2/5
Truck-relevant
Service soon
Severity
Service soon
Cruise Control Multi-Function Input B Stuck
Code
P0590
Category
Powertrain
Subsystem
Speed
Truck-relevant
Yes
What this means for truckers
P0590 (Cruise Control Multi-Function Input B Stuck) — secondary cruise input switch stuck.
Before you replace parts — try this first
P0590 on the Speed system is most often cruise switch button physically stuck or sticking from dirt or a spill — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Cruise control is disabled or cancels by itself, and set speed may creep up or down unexpectedly before the code sets. The check-engine light may come on. The engine otherwise runs normally.
Common causes
- CommonCruise switch button physically stuck or sticking from dirt or a spill ($80–$350)
- CommonInternally shorted multi-function switch ($80–$350)
- OccasionalWiring shorted between switch circuits in the column or clockspring ($150–$650)
- RareFault in the ECM or body-controller input ($900–$2500)
How to fix
Watch the input B status on a scan tool and confirm it changes cleanly when you press and release the button
When to use: First step
Check that the buttons move freely, then clean or replace the switch
When to use: When the status stays active after you release the button
Unplug the switch and see whether the input clears; if it doesn't, trace the wiring for a short between circuits
When to use: When replacing the switch doesn't fix it
Clear the codes and test cruise set, resume and cancel on a road test
When to use: After any repair
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P0500 — Vehicle Speed Sensor Malfunction
- → P0501 — Vehicle Speed Sensor Range/Performance
- → P0502 — Vehicle Speed Sensor Low Input
- → P0503 — Vehicle Speed Sensor Intermittent/Erratic/High
- → P0506 — Idle Control System RPM Lower Than Expected
Frequently Asked Questions
Can I drive with code P0590?
P0590 is severity 2 — service this week. Not an immediate stop, but ignoring it usually compounds the problem. Most common cause for this code is a worn sensor or minor performance fault that won't strand you today but will get more expensive the longer you wait.
How much does it cost to fix P0590 on a commercial truck?
Total repair cost ranges $80–$2500 depending on the root cause. The cheapest fix is usually the first one listed below — Cruise switch button physically stuck or sticking from dirt or a spill — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will P0590 fail a DOT inspection?
P0590 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between P0590 and related codes?
P0590 is closely related to: P0500 (Vehicle Speed Sensor Malfunction), P0501 (Vehicle Speed Sensor Range/Performance), P0502 (Vehicle Speed Sensor Low Input), P0503 (Vehicle Speed Sensor Intermittent/Erratic/High). These codes share the same subsystem (speed) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only P0590 is set without the companions, the issue is more isolated.
How do I prevent P0590 from coming back after a repair?
For P0590 (Cruise Control Multi-Function Input B Stuck), prevention centers on the speed system. Inspect wheel speed sensor wiring at PM (rodents love it). Keep ABS tone rings clean.