P0596 OBD-II Trouble Code: Cruise Control Servo Control Circuit High

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0596 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0596 code

P0596 is a diagnostic trouble code (DTC) for "Cruise Control Servo Control Circuit High". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0596 DIAGNOSTIC Get a fair and transparent estimate upfront

P0596 code definition

The P0596 diagnostic trouble code is an indication that there is an issue with the cruise control servo control circuit.

Related Trouble Codes:

What the P0596 code means

When the cruise control feature is in use, vehicle speed is automatically controlled by the Powertrain Control Module (PCM), the cruise control module, and the servo control unit. The Powertrain Control Module (PCM) receives a signal from the cruise control module as to the desired speed of the vehicle. The servo control unit receives information from the Powertrain Control Module (PCM) and cruise control module as to the required position of the throttle plate. The servo control unit will then open or close the throttle plate to maintain the desired speed of the vehicle. The P0596 diagnostic trouble code is stored when the cruise control module is not sending the proper speed signal to the Powertrain Control Module (PCM) necessary to control vehicle speed and the cruise control servo control unit is giving an abnormal voltage or resistance reading.

What causes the P0596 code?

  • Faulty cruise control servo control unit

  • Blown fuses

  • Faulty cruise control servo control wires that are frayed, broken, or shorted

  • Faulty cruise control servo control connectors that are damaged or corroded

  • Liquid spilled onto the cruise control switch

What are the symptoms of the P0596 code?

How does a mechanic diagnose the P0596 code?

  • Diagnostic trouble codes should be diagnosed in the order that they appear in the powertrain control module (PCM).
  • Use an OBD-II scanner to collect all trouble codes that have been stored by the powertrain control module (PCM) as well as freeze frame data.
  • Inspect the cruise control servo control wiring for frays, breaks, and shorts. Repair or replace damaged wiring as necessary.
  • Inspect the cruise control servo control connectors for damage and corrosion. Repair or replace connectors as necessary.
  • Check the cruise control switch for proper operation. Also inspect the cruise control switch wires for damage.
  • Clear all diagnostic trouble codes from Powertrain Control Module (PCM) and operate the vehicle to see if the P0596 diagnostic trouble code comes back.
  • If the P0596 trouble code comes back, check the fuse for the cruise control system. Repair or replace as necessary.
  • Check the cruise control switch for proper operation. Also inspect the cruise control switch wires for damage.
  • In vehicles with a vacuum controlled cruise control system, inspect vacuum lines, one-way check valve, engine vacuum, and engine vacuum components for damage.
  • Repair or replace vacuum lines and engine components as necessary.
  • Inspect the cruise control servo and the throttle cable to the servo for damage. Repair or .replace as necessary.
  • Clear all diagnostic trouble codes from Powertrain Control Module (PCM) and operate the vehicle to see if the P0596 diagnostic trouble code comes back.
  • If the P0596 trouble codes come back, use a digital volt ohm meter to test cruise control servo control unit and the cruise control switch for proper voltage and continuity.
  • If the test results of the cruise control servo control unit do not meet the manufacturer’s predetermined specifications the cruise control servo control unit will need to be replaced.
  • If the test results of the cruise control switch do not meet the manufacturer’s predetermined specifications, the cruise control switch will need to be replaced.

Common mistakes when diagnosing the P0596 code

The most common mistake made with this code is overlooking blown fuses. Other components should not be replaced without first inspecting the fuses to ensure they are working properly. When components are replaced unnecessarily, it is a waste of time and money and may not resolve the problem.

How serious is the P0596 code?

A diagnostic trouble code is normally considered serious when it causes driveability issues or a change in performance.When this code is stored in the Powertrain Control Module (PCM), the cruise control system will be disabled. This may be considered an inconvenience, but is not considered serious. The P0596 diagnostic trouble code should however, be diagnosed and repaired as soon as possible.

What repairs can fix the P0596 code?

  • Replace cruise control servo control unit

  • Replace blown fuses

  • Repair or replace cruise control servo control wiring that is frayed, broken, or shorted

  • Repair or replace cruise control servo control connectors that are damaged or corroded

  • Replace cruise control switch

Additional comments for consideration regarding the P0596 code

Liquid spilled on the cruise control buttons has been known to cause the P0596 diagnostic trouble code. Other common causes are faulty wiring and blown fuses.

Need help with a P0596 code?

YourMechanic offers certified mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6220.

trouble codes
OBD-II
P0596

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0596 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

4,829

Rating Summary
4,442
187
48
28
124
4,442
187
48
28
124

Walter

44 years of experience
64 reviews
Walter
44 years of experience
Jeep Grand Cherokee - Check Engine Light is on - Tulsa, Oklahoma
Went above and beyond my expectations, as i was very nervous about this type of service! But to my surprise, I am absolutely satisfied with the service ! Would recommend 100X to all i know! Thanks for the care and information and time you put in to my qoute and truck@

Keith

16 years of experience
279 reviews
Keith
16 years of experience
BMW 535i xDrive - Check Engine Light is on - Kissimmee, Florida
Very personable, knowledgeable person, who provided information on my car that I was not aware of. The overall experience was great and I would definitely refer this company to my family and friends.

Luis

13 years of experience
20 reviews
Luis
13 years of experience
Audi A3 - Check Engine Light is on - Van Nuys, California
Luis was awesome. Very knowledgeable and a down to earth person. Would highly recommend and plan on using him in the future for any repair that I need!

Joel

19 years of experience
742 reviews
Joel
19 years of experience
Acura RL - Check Engine Light is on - Jacksonville, Florida
very knowledgeable and precise. able to fix electrical issues in my car. Right on time for the appointment.

More related articles

P0848 OBD-II Trouble Code: Transmission Fluid Pressure Sensor/Switch B Circuit High
P0848 means there is an issue with the transmission fluid sensor circuit, possibly due to a faulty sensor, low fluid level, or fluid contamination.
P0204 OBD-II Trouble Code: Injector Circuit Malfunction - Cylinder 4
P0204 code definition Injector Circuit Malfunction - Cylinder 4 What the P0204 code means The Engine Control Module (ECM) runs checks...
Are Lights the Only Thing the OBD Uses to Warn the Driver of Issues?
If If your car was manufactured after 1996, it has an OBD II system that monitors emissions and other systems on board. While it’s primarily focused on emissions, it can also report other problems that are only peripherally related to...

Related questions

No start

Hello. A no start condition can be caused by a wide variety of issues, and from what you describe it would appear that the vehicle may have more than one issue. If spraying brake cleaner into the intake helped...

Check Engine Light is on and Autozone read: Trouble Code P0138 O2 Sensor Bank 1 Sensor 2 High Voltage

Hello. If it has a code for an oxygen sensor then that may be the issue. The thing about the oxygen sensors though is that they can give a false reading if there is something else going on with the...

Check engine light on 1998 Audi A4

Any good mechanic can check them out. Here's the problem that you've got though--when there's a linking error, either the nanoport isn't working right because one of the pins is bent or there's wiring short somewhere in the computer system...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com