P2711 OBD-II Trouble Code: Unexpected Mechanical Gear Disengagement

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

SCHEDULE P2711 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2711 code

P2711 is a diagnostic trouble code (DTC) for "Unexpected Mechanical Gear Disengagement". 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 for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 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$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P2711 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light

P2711 trouble code definition

A P2711 fault code is generated when the transmission control module (TCM) or powertrain control module (PCM) detects a problem between the output shaft speed signals and the input shaft speed signals. The control module perceives this problem as a mechanical disengagement of the gears, and can result in poor shift quality and drivability issues.

What the P2711 code means

An unexpected mechanical gear disengagement occurs when the PCM suspects that the output shaft speed sensor is malfunctioning in some way. The way the code is programed varies from manufacturer to manufacturer, but the basic idea is that the system will detect an error when the gears are, or are about ready, to shift. If the output speed is not gradually increasing (an increase that occurs until a gear shift is complete), as it does with normal functioning, then the system will detect an error. Some makes and models will require many system failures before a service engine light is triggered.

What causes the P2711 code?

The most common causes of the P2711 code are due to a malfunctioning output speed sensor or an input speed sensor. There can also be other mechanical failures that cause the code to trigger including:

What are the symptoms of the P2711 code?

There are many noticeable associated symptoms of the P2711 code, but this is not always the case:

How does a mechanic diagnose the P2711 code?

The P2711 code can be properly diagnosed with an advanced scanner (OBD-II scan tool) and a digital voltmeter, and, in some cases, an oscilloscope. If the scanning indicates an erratic output signal, as opposed to an erratic input signal, then the technician can assume that the unexpected mechanical gear disengagement is due to a problem with the output speed sensor, and make the diagnosis as such.

In other cases, mechanical problems are possible, i.e. damaged gears and/or drive shafts. At this point, any leaks in the transmission should be repaired, and the proper transmission fluid should be drained and refilled. If the drained transmission fluid is “burnt”, the transmission will most likely be irreparable. If not, the transmission will be used under normal conditions for tests and reassessment.

Common mistakes when diagnosing the P2711 code

One common mistake when misdiagnosing the P2711 code is attempting to diagnose the problem as a fault with engine speed, rather than a problem with internal transmission speeds. Another common misdiagnoses is replacing the vehicle speed sensor, when the problem is in fact the transmission. A proper visual inspection of the transmission, along with a digital inspection of the electrical system components with the proper tools, can help avoid misdiagnoses. Additional inspections and tests may be necessary.

How serious is the P2711 code?

The P2711 code might cause the following problems with your vehicle:

  • Harsh or failed shifting
  • Decrease in fuel economy
  • Wild fluctuating of the speedometer
  • Complete failure of the speedometer
  • Engine stalling when coming to a stop
  • Engine misfire, stall, or hesitation

In some cases, a check engine light may be the only noticeable symptom of a P2711 fault. Even if there are no noticeable problems while driving, you should have the vehicle checked immediately to determine and resolve the issue to avoid future damages and/or dangers while using a vehicle while the Service Engine light is triggered.

What repairs can fix the P2711 code?

The most common procedures to resolve problems associated with the P2711 code are as follows:

  • Use a code reader/scanner, voltmeter, or oscilloscope to diagnose the code and to determine how the input and output speed signal is registering by the PCM.

  • A visual inspection of all wiring, connectors and components will be part of the initial inspection. Any wires that are damaged, contaminated, or corroded will need to be replaced.

  • Even if the PCM is registering the input and/or output signal as erratic, indicating an unexpected mechanical gear disengagement, it is possible the error is coming from the transmission itself, from a failing gear or shaft. In any case, the transmission will need to undergo a thorough inspection. In some cases, the transmission will need to be taken out and/or replaced.

  • In the event that the transmission checks out after inspection, one or more sensors might need to be replaced.

  • A technician might clear the OBD-II codes to see which ones return. If no codes return, the situation might be intermittent, which is difficult to diagnose. In some cases, the situation might need to worsen before a correct diagnosis can be made.

  • In rare cases, after testing, a technician might need to repair or replace certain electrical components of the transmission control system, according to manufacturer’s specifications. Afterwards, they will retest to make sure repairs are up to spec with manufacturer’s standards. Any electrical replacements will require reprogramming of the PCM.

Additional comments for consideration regarding the P2711 code

It is possible that electrical-related codes occur constantly or intermittently. In the situation where the codes occur intermittently, additional time might be necessary for the situation to worsen before the issue can be properly diagnosed. The nature of a triggered P2711 code is diverse, and a solution can range from easy to diagnose and fix, to time consuming and difficult. Depending on your vehicle’s make, model and year, determining the root cause of the issue and resolving it might take several hours.

Most diagnoses, when tested with a voltmeter and/or oscilloscope, are very specific and involve many systems and components. If tests of the electronic system determine that the system is functioning properly, further inspection of the transmission will be necessary to determine whether or not the issue is mechanical, which can also require multiple test and several hours.

In some cases, and usually with vehicles with high mileage, the transmission might need to be replaced, or undergo a rebuild. However, replacing certain parts based on an assumed common issue is not recommended since no problem has been positively diagnosed. Assuming a quick fix could cause more problems, or simply render the issue unsolved.

Need help with a P2711 code?

YourMechanic offers certified mobile 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 1-888-312-6876.

trouble codes
Check Engine Light
P2711

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

SCHEDULE P2711 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

4.5/5

Number of Reviews

3,696

Rating Summary
3,372
162
42
24
96
3,372
162
42
24
96

Jose

22 years of experience
57 reviews
Jose
22 years of experience
Very helpful
1998 DODGE GRAND CARAVAN - CHECK ENGINE LIGHT IS ON INSPECTION - VALLEJO, CALIFORNIA

Peter

40 years of experience
1059 reviews
Peter
40 years of experience
I was extremely impressed not only with his knowledge, but work ethic as well. It was extremely refreshing. Wonderful work.
2007 HYUNDAI TIBURON - CHECK ENGINE LIGHT IS ON - PHOENIX, ARIZONA

Matthew

30 years of experience
363 reviews
Matthew
30 years of experience
Matthew is "MyMechanic". LOL I've convinced my husband to use his services instead of going to the dealership. Thanks Matthew for you thorough review of our Jeep Commander. Matthew is friendly, knowledgeable and confident in his business. We will most definitely call him again. I have referred this service to a number of friends, have no idea if they have contacted him or not. Will giving referrals.
2006 JEEP COMMANDER - CHECK ENGINE LIGHT IS ON - NEWPORT NEWS, VIRGINIA

Angelo

29 years of experience
76 reviews
Angelo
29 years of experience
Angelo is very knowledgeable. Showed up on time. I am looking forward to working with him again
2000 ISUZU TROOPER - CHECK ENGINE LIGHT IS ON - PLANO, TEXAS

More related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...

Related questions

Q: Vehicle turns off at any rpm, at idle or highway speeds, without stumbling or warning.

This kind of a stalling issue can be caused by a variety of problems. They are typically caused by ignition faults, wiring faults, and fuel issues. Although you do not have a Check Engine Light on, you should still scan...

Q: P101 keeps coming on Yukon 2003 after replacing with a new one, cat converters were installed fixing the p420 problem,

Claimed by Jay Safford

Q: Why after changing the power steering pressure sensor I still get the check engine light stating sensor failure?

When you scanned the computer and got a code for the power steering pressure switch, it did not necessarily mean to simply replace the sensor to fix the code. The code you got directs you to a pinpoint test that...

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