The P0591: Cruise Control Multi-Function Input ‘B’ Circuit Range/Performance refers to a problem where the cruise control system’s multi-function input ‘B’ circuit is operating outside of its expected range or performance parameters. This could be caused by a faulty switch, wiring issues, or a malfunctioning cruise control module, leading to improper cruise control functionality.
P0591 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0591: Cruise Control Multi-Function Input ‘B’ Circuit Range/Performance |
| Is it serious? | No, but it can prevent the cruise control system from functioning correctly. |
| Possible causes | – Faulty multi-function input ‘B’ switch – Wiring issue – Faulty cruise control module |
| How to diagnose? | – Test multi-function input ‘B’ switch – Inspect wiring and connectors – Test cruise control module |
P0591 Meaning
The P0591 code indicates that the multi-function input ‘B’ circuit in the cruise control system is either outside its expected range or not performing properly. This can be caused by a malfunctioning switch, wiring problems, or issues with the cruise control module, resulting in impaired cruise control operation.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for any additional codes related to the cruise control system. | OBD-II Scanner |
| Test the Multi-Function Input ‘B’ Switch | Use a multimeter to test the multi-function input ‘B’ switch for correct range and performance. | Multimeter |
| Inspect Wiring and Connectors | Inspect the wiring and connectors for damage, loose connections, or corrosion. | Flashlight, Multimeter |
| Test the Cruise Control Module | Verify that the cruise control module is functioning correctly and within specified performance range. | Diagnostic Tool, Multimeter |
| Clear the Code and Test | After making repairs, clear the code using the OBD-II scanner and test the cruise control system to ensure it works properly. | OBD-II Scanner, Vehicle Manual |
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