P2749 OBD-II Trouble Code: Intermediate Shaft Speed Sensor C Circuit

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

SCHEDULE P2749 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2749 code

P2749 is a diagnostic trouble code (DTC) for "Intermediate Shaft Speed Sensor C Circuit". 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 P2749 DIAGNOSTIC Get a fair and transparent estimate upfront

Check Engine Light

P2749 code definition

The P2749 trouble code identifies irregular shaft speed.

What the P2749 code means

When code P2749 is stored by a vehicle’s PCM (Powertrain Control Module), it’s because it received an input signal that was sent from a transmission intermediate shaft speed sensor circuit. Receiving such a signal is normal while the vehicle is in use. The PCM is responsible for monitoring the vehicle’s operation.

However, If the code is logged it’s because the actual signal was erratic, irrational or incorrect, this is a problem that needs to be recorded. Every make and model is designed with different ranges to accept for intermediate shaft speeds, but they all follow the same general concept: its speed is meant to gradually increase until a shift point is finally reached. Therefore, the real issue is that the transmission can’t implement a sensible shift strategy if it isn’t being given an intermediate shaft speed signal that is based on accurate information.

What causes the P2749 code?

The majority of the time this code gets stored, it’s because either the intermediate shaft speed sensor, input speed sensor or output sensor is defective. That being said, some other common causes are:

  • Wiring circuits or connectors that are damaged, corroded, open or shorted

  • Malfunctioning shift solenoids

  • Defective valve body

  • Faulty engine drivability sensors (usually the engine temperature sensor)

  • Transmission fluid that is dirty or contaminated (this would restrict flow) Lastly, if none of the above checks out, the PCM could be to blame. This is very rare though.

What are the symptoms of the P2749 code?

As we touched on earlier, the most notable symptom will be that the vehicle’s automatic transmission doesn’t shift. The driver will see their RPMs building to the point that a shift is supposed to occur, but nothing does. A Check Engine Light should come on after this code is stored. However, some models were designed to delay the Check Engine Light until the issue has been detected at least a couple of times.

How does a mechanic diagnose the P2749 code?

A mechanic will begin their diagnosis by using an HBD-II scanner to take a reading from the vehicle. Once they see the P2749 code, they’ll know that their next step is to examine the intermediate shaft speed sensor, input speed sensor and output sensor. If those all look fine, they’ll move to inspecting the wires and connectors that attach to the PCM. Then they’ll look at the shift solenoids and the valve body if necessary.

Common mistakes when diagnosing the P2749 code

A lot of mistakes can be made when trying to diagnose the P2749 code. Many mechanics, upon hearing a description of the problem, will skip using their OBD-II scanner and simply assume it’s a vehicle speed issue. They may also think there is something wrong with the transmission, that the engine must have simply backfired, that fuel delivery is being impeded or that the driver made some kind of mistake. Even if the mechanic does understand that a P2749 code has been stored, they could still misdiagnose the source and replace the vehicle speed sensor unnecessarily. Given how many other possibilities there are for causing the code, there’s a very good chance this replacement won’t do anything.

How serious is the P2749 code?

Fortunately, this code doesn’t represent a dangerous problem. That being said, a vehicle that won’t shift is going to be difficult to drive. It would be unrealistic to think that automobile could be taken on the highway while P2749 code is present.

What repairs can fix the P2749 code?

Repairs could involve any of the following:

Additional comments for consideration regarding the P2749 code

Although this isn’t a problem that will put anyone’s life at risk, it should be addressed right away to prevent it from causing more serious issues.

Need help with a P2749 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 1-800-701-6230.

P2749
trouble codes
Check Engine Light

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

SCHEDULE P2749 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

3,788

Rating Summary
3,460
163
43
24
98
3,460
163
43
24
98

Chris

17 years of experience
309 reviews
Chris
17 years of experience
Chris was very professional. He listened to me, then went right to work checking my vehicle. He explained what was needed and assured me he could do the work. I believe he can and will get my car in tip-top shape for my summer traveling.
2008 JEEP PATRIOT - CHECK ENGINE LIGHT IS ON - SHERWOOD, OREGON

Diego

18 years of experience
208 reviews
Diego
18 years of experience
Extremely professional, polite with attentive respect on time and thoroughly described in detailed on all problems!
2004 LAND ROVER RANGE ROVER - CHECK ENGINE LIGHT IS ON - AVONDALE, ARIZONA

Chet

38 years of experience
393 reviews
Chet
38 years of experience
Really good.
2003 BMW Z4 - CHECK ENGINE LIGHT IS ON - CHULA VISTA, CALIFORNIA

James

27 years of experience
331 reviews
James
27 years of experience
James is absolutely amazing...He did a Tune up & diagnostic for the check engine light on my 2005 Infiniti. Not only was he on time and very professional, but he made everything very easy to understand and gave me options that fit my budget for dealing with, what turned out to be an oil leak.. i hate when mechanics hit me with a bunch of terms and responses that the average person who knows nothing about cars wouldn't understand..And then pressure you into paying top dollar for problems they claim to be imminent... James is very down-to-earth and I will definitely be requesting him and/or the services of your mechanic for now on. P.S. Meineke wanted to charge me $300 more for the same exact service
2005 INFINITI G35 - CHECK ENGINE LIGHT IS ON - ORLANDO, FLORIDA

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...
P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
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: My Pontiac G6 won't crank and wont start

I believe your "no crank" issue is the passlock security system has locked things down because of what it perceived as a "battery swap". If the car restarted after the jump as you indicate, the ECM is probably OK. The...

Q: ECU and related components

Your ECU would have to be programmed. Although it is possible nowadays for consumers to download the software from the OEM for a fee, you need an interface cable and knowledge of the programming steps. Once you add up the...

Q: Engine stumbles around 3000 RPM.

Hi there. The engine could be stumbling for the coil pack or distributor may not be functioning correctly. As the coil pack or distributor gets old, the parts tend to become weak and is not able to send an electrical...

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