Failed cruise servo position sensor inside the servo assembly; Corroded or backed-out terminals in the servo position sensor connector; Chafed or open wiring between the servo position sensor and the powertrain control module; Poor ground connection at the servo mounting or chassis ground point; Sticking or binding cruise servo linkage preventing the sensor from tracking commanded position; Faulty powertrain control module driver circuit for the sensor reference or signal return

DTC codes / GM codes / P1565

P1565 · GMCruise Servo Position Sensor

Q: What does code P1565 mean?

Cruise Servo Position Sensor. P1565 on a GM vehicle indicates that the cruise control servo position sensor circuit has reported a voltage or signal outside the range the powertrain control module expects during self-test or operation. The computer compares the sensor's feedback against commanded servo position and flags the code when the two do not agree or the signal is electrically implausible.

P1565 on a GM vehicle indicates that the cruise control servo position sensor circuit has reported a voltage or signal outside the range the powertrain control module expects during self-test or operation. The computer compares the sensor's feedback against commanded servo position and flags the code when the two do not agree or the signal is electrically implausible.

SystemPowertrain

Code typeGM specific

SeverityLow

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

Cruise control may not engage at all when you press the set button
Cruise control engages but disengages unexpectedly on its own
The cruise control indicator lamp may flash or fail to illuminate
Vehicle speed may surge or hunt slightly while cruise is active
Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

Failed cruise servo position sensor inside the servo assembly
Corroded or backed-out terminals in the servo position sensor connector
Chafed or open wiring between the servo position sensor and the powertrain control module
Poor ground connection at the servo mounting or chassis ground point
Sticking or binding cruise servo linkage preventing the sensor from tracking commanded position
Faulty powertrain control module driver circuit for the sensor reference or signal return

How to diagnose and fix it

Connect a scan tool and record freeze-frame data for P1565, then clear the code and verify whether it returns immediately or only after a drive cycle
Inspect the cruise servo connector and harness for corrosion, pushed pins, or chafed insulation, and repair any damaged terminals
Measure reference voltage and signal return voltage at the servo position sensor connector with the key on and compare against GM service information specifications
Check the servo ground circuit for excessive resistance using a voltage drop test while wiggling the harness
Command the cruise servo through the scan tool bidirectional controls and watch sensor position feedback for smooth, proportional movement
If the sensor signal is erratic or out of range while the servo moves freely, replace the cruise servo assembly and recheck
After repair, perform a road test engaging cruise control at highway speed and confirm the code does not reset

What the servo position sensor really does

The cruise servo position sensor is a feedback potentiometer inside the servo, so a worn resistive track often causes an intermittent code that only sets after the servo has been cycled several times.
A binding throttle cable or cruise linkage can hold the servo against its commanded position and set P1565 even when the sensor and wiring are electrically perfect.
Technicians frequently replace the servo only to find the real fault is a corroded ground behind the left kick panel or at the servo bracket, so always voltage-drop the ground before condemning parts.
P1565 can be stored by a low or weak battery during cranking because the module sees an implausible sensor voltage at key-on, so check battery condition and clear the code before deeper diagnosis.
On some GM platforms the cruise servo shares a reference voltage with other sensors, so a shorted sensor elsewhere on that circuit can pull the reference down and set P1565 as a bystander code.

Can I keep driving with P1565?

The vehicle remains safe to drive because P1565 disables or degrades cruise control only and does not affect throttle response or braking. Avoid using cruise control until the fault is repaired, since an unexpected disengagement or speed surge can be distracting in traffic.

Tools that help

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Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.