Guide To P0593 OBD Error Code Solutions

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The Cruise Control System is an important function that if malfunctioned can affect the drivability, throttle response, and the speed of the vehicle. This can be due to faulty components in relation to the cruise control system and can even be dangerous. This directly indicates problem with the Cruise Control Circuit and flashes OBD code P0593 error in the system.

OBD code P0593 error is defined as Cruise Control Multi-Function Input “B” Circuit High.

The multi-function input circuit is an important part of the cruise control system, which is controlled by the cruise control module and the powertrain control module (PCM). These two control modules work in tandem to automatically control the vehicle’s speed. When the PCM notices that the speed can no longer be controlled, the cruise control system will be thoroughly checked. If the PCM notes that the cruise control multi-function input circuit is producing a voltage or resistance level that is not within the standard range, the P0593 code will be triggered.

What causes this problem with the Cruise Control Multi-Function Input "B" Circuit High?

• Stuck, broken or missing cruise control switch
• Wiring Problem due to damage, water intrusion, corrosion etc.
• Speed Control Switch Faulty
• Open or shorted speed control switch harness
• Cruise control connector malfunction
• Blown Fuses that will require replacement
• Cruise control button/switch causing abnormal mechanical operation

1. Speed Sensor - Check and replace the speed sensor so that the cruise control system can anticipate the speed properly for correct decision. Buy new speed sensor now!
2. Speed Sensor Connector - If the sensor connector is not working properly, it should be replaced with immediate effect. Replace new sensor connector now!
3. Cruise Control Switch - Damaged switch should be replaced as the cruise control might not function correctly. Buy and replace it with new switch now!
4. Cruise Control Connector - Replace the cruise control connector if found damaged for the proper wiring functions. Buy new connectors now!
5. Cruise Control Fuse - Always check for blown fuses first and replace it immediately. Buy new fuses from us!
6. Powertrain Control Module - P0593 code can also display due to some defects in the PCM. So it is very important to replace the powertrain control module components to get the correct readings. Buy new components form us now!
7. Diagnostic Tool - Choose from our wide variety of diagnostic tools to detect and correct the OBD code error.

We at Parts Avatar Canada care for our customers, and that’s why we will help you to diagnose P0593 code by listing out some major symptoms. They are mentioned below as follows:

Common Symptoms

• Abnormal vehicle speeds with cruise control active
• Cruise control inoperative
• Cruise control light illuminated regardless of switch position
• Cannot set cruise control to desired speed
• A Service Engine Soon Lamp may or may not illuminated along this code

Have a look at some ways with which you can correct the P0593 code:

• Replacement of speed sensor
• Replacement of cruise control sensor
• Faulty wiring and connector replacement
• Blown fuses replacement
• Repair or reprogram PCM faults

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of Speed Control Switch, Speed Control Switch Harness, Fuses, Cruise Control Switch, Cruise Control Connector, Electronic Control Module and many more. Now all your problems would vanish within no time.

Learn the ways with which you can correct this P0593 trouble code:

• Make use of OBD-II scanner and voltmeter to diagnose any error code issue. 

• Check fuses, wiring harnesses, and switch for chafing, pinched wires, or obvious damage. Check connectors for bent or broken pins or corrosion and that they are firmly seated. Repair or replace as necessary.
• Depending on the vehicle, you may need to do resistance or continuity checks. Some switches use just two pins, each switch position applying a different resistance value to the circuit. Other switches use multiple pins, each switch closing or opening circuits. Check your EWD and repair manual to be sure which method your vehicle’s cruise control system switch is using.
• Disconnect the ECM and check the circuit accordingly. If continuity or resistance is correct, suspect a PCM fault or intermittent circuit problem. Do not condemn the PCM until you have rechecked the rest of the system.
• If continuity or resistance is incorrect, suspect a faulty switch or spiral cable. Repeat the check at the switch itself.
• If switch continuity or resistance is correct, suspect the spiral cable. You can check all circuits in the spiral cable end-to-end, but make sure the ignition is off, battery is disconnected, and all connectors are disconnected. If switch continuity or resistance is incorrect, replace the switch.

Common Mistakes When Diagnosing the P0593 Code

It is essential that mechanics follow the protocol to avoid erroneous repairs, and don’t overlook simple fixes. Failure to do so often results in blown fuses – a very simple fix – being overlooked.

• Check for cruise control faults
• Cruise control inoperative
• Speed Sensor failure
• Speed Sensor Connector fault
• Cruise control light illuminated regardless of switch position
• Powertrain Control Module fault