P0590

Code

Generic P — Powertrain

Cruise Control Multi-Function Input B Circuit Stuck

Brand: Generic

Type: P — Powertrain

Views: UK: 30 EN: 43 RU: 32

AI status

Completed

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Page language: EN

Causes

Short to battery or short to ground in the input B wiring
Open circuit or high resistance in harness or connector
Corroded or loose connector at switch, clock spring, or module
Failed cruise control multi-function switch or steering wheel clock spring
Faulty Body Control Module (BCM) or Cruise Control Module
Blown fuse or poor power/ground to switch/module

Symptoms

Cruise control inoperative or cuts out when engaged
Cruise set/resume not responding or intermittent operation
Steering wheel multi-function buttons (cruise) nonfunctional
Possible illuminated cruise/vehicle message or malfunction indicator
Erratic cruise behavior or inability to maintain set speed

What to check

Scan for codes and freeze frame data; note related or network codes
Inspect fuses and relays for cruise control and BCM power/ground
Visually inspect steering column connectors, clock spring, and harness for damage or corrosion
Backprobe the multi-function switch connector with key ON and observe signal
Wiggle test wiring while monitoring signal to reproduce fault
Check continuity and resistance from switch pin to BCM/ECM

Signal parameters

Typical input is a digital/logic signal: nominally 0 V (low) and ~5 V (high) — verify against vehicle spec
Closed switch should show near 0 ohms continuity; open is infinite resistance
Some systems use pulsed signals (frequency or PWM) — expected steady state or toggling when buttons pressed
No rapid voltage spikes or constant mid-level voltage (e.g., ~2–3 V) — mid-level indicates wiring fault or partial short

Diagnostic algorithm

Retrieve PCM/BCM data and note conditions when code sets. Clear codes and try to re-create the fault.
Inspect fuses, wiring, and connectors for obvious damage, corrosion, or water entry at the steering column and BCM.
With ignition ON, backprobe the multi-function input B pin at the switch connector. Observe resting voltage and change when pressing associated buttons.
If signal is stuck, check for short to battery (measure voltage with switch disconnected). If voltage present with switch removed, suspect short to power or module output fault.
With switch connected, measure continuity and resistance from switch pin to the BCM/ECM connector; repair any opens or high resistance.
Perform wiggle tests on the harness and clock spring while monitoring signal to detect intermittent faults. Inspect/replace clock spring if steering wheel movement affects the signal.

Likely causes

Damaged wiring or pin pushed out at steering column connector
Failed multi-function (cruise) switch or internal contact stuck
Defective or torn clock spring causing intermittent/shorted signal
Corroded connector pins causing stuck voltage
Poor ground at BCM or switch return

Fault status

⚠️ Status

Cruise control multi-function input B circuit indicates a stuck or abnormal signal. Cruise control/multi-function buttons may be disabled until repaired.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours