OBD-II Code P0585 — What It Means & How to Fix It

What Does This Error Mean?

P0585 means the two cruise control multi-function switch inputs are not agreeing with each other. Some vehicles have redundant cruise control switch circuits for safety. When the two circuits give conflicting readings, the module stores P0585 and disables cruise control. This is a safety feature — conflicting switch signals could cause unexpected cruise control behavior.

Affected Models

All vehicles 1996+ with dual cruise control switch inputs
Common in Ford and Lincoln vehicles
Common in GM full-size trucks and SUVs
Common in Dodge Ram trucks
Less common on vehicles with a single switch input circuit

Common Causes

One of the two cruise control switch inputs has a fault (check for companion codes P0580 or P0581)
Faulty cruise control switch sending conflicting signals on the two circuits
Wiring fault affecting only one of the two switch input wires
Corroded connector causing one circuit to read differently than the other
Defective body control module or powertrain control module unable to reconcile the two inputs

How to Fix It

Scan for all stored codes. P0585 is often stored alongside P0580 or P0581 which indicate which input circuit has the problem. Fix companion codes first.

Solving the individual circuit fault often resolves P0585 automatically.
Inspect the cruise control switch connector carefully. Look for any terminals that appear pushed back slightly, which would cause one circuit to have poor contact while the other is fine.

Use a straightened paper clip to gently press each terminal in and confirm it locks back into place.
Clean the cruise control switch connector with electrical contact cleaner and reconnect firmly. Clear the code and test if the cruise control works and the code stays away.

Sometimes oxidized terminals cause one input to read slightly off, triggering the correlation fault.
If the code returns, use a scan tool with live data to view both cruise control switch inputs simultaneously while pressing each switch button. One of the two inputs will show an incorrect value.

This step requires a scan tool that can display manufacturer-specific PIDs (parameter IDs), not just generic OBD-II data.
Replace the cruise control switch assembly if one input is confirmed to be out of range. Clear codes and verify normal cruise control operation.

On many vehicles the cruise control buttons are on the steering wheel and the entire switch cluster is replaced as a unit.

When to Call a Professional

If P0585 is accompanied by P0580 or P0581, fix those codes first. P0585 on its own with no companion codes usually points to a switch or connector problem. A dealer or shop with factory scan tools can watch both inputs simultaneously to identify which one is out of range. Expect $75 to $150 for diagnosis.

Frequently Asked Questions

Why do some vehicles have two cruise control switch inputs?

Redundant inputs are used as a safety measure. If both inputs must agree before cruise control engages, a single failed wire cannot accidentally activate or hold cruise control. When they disagree, the system shuts down cruise control entirely rather than risk acting on bad data.

Can P0585 fix itself?

It is unlikely to fix itself. The code indicates the two inputs are consistently out of agreement. Cleaning the connector may help if the cause is oxidation, but a failed switch will continue to give conflicting readings until replaced.

Does P0585 affect anything besides cruise control?

On most vehicles, no. Cruise control is a convenience feature that is independent of core engine and safety systems. Braking, steering, and engine operation are not affected by P0585.