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

Our certified mechanics come to you · 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 $114.99 . Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.0 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 $114.99 $20.0
Toyota $114.99 $20.0
BMW $124.99 $20.0
SCHEDULE P2749 DIAGNOSTIC Get a fair and transparent estimate upfront

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.

Check Engine Light
trouble codes
P2749

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2749 code.

SCHEDULE P2749 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(7400)

Rating Summary
6879
249
58
41
173
6879
249
58
41
173
 at YourMechanic

David

13 years of experience
393 reviews
David
13 years of experience
Chevrolet Malibu L4-2.4L - Check Engine Light is on Inspection - Marietta, Georgia
He explained everything to me in detail on what I needed to know about my car. Definitely recommend him for getting the job done.
 at YourMechanic

Raymond

37 years of experience
402 reviews
Raymond
37 years of experience
Toyota Camry L4-2.2L - Check Engine Light is on - Las Vegas, Nevada
Raymond did a great job however I was charged for two hours labor and he was only here less than 45 minutes. should I expect this on future appointments with your mechanic ?
 at YourMechanic

Shane

17 years of experience
217 reviews
Shane
17 years of experience
Volkswagen EuroVan V6-2.8L - Check Engine Light is on Inspection - Austin, Texas
Arrived on time. Explained the issues he found and how he will fix it. I have parts on order and will schedule an appointment to have Shane install the parts when they arrive.
 at YourMechanic

Kanstantsin

19 years of experience
51 reviews
Kanstantsin
19 years of experience
Ford F-150 V8-4.6L - Check Engine Light is on Inspection - Littleton, Colorado
Kanstantsin arrived early. Was very courteous and professional. Will highly recommend to anyone. Thank you Kanstantsin.


More related articles

P2197 OBD-II Trouble Code: O2 Sensor Signal Stuck Lean Bank 2 Sensor 1
P2197 code definition O2 Sensor Signal Stuck Lean Bank 2 Sensor 1 What the P2197 code means This code is usually an...
P2271 OBD-II Trouble Code: O2 Sensor Signal Stuck Rich Bank 1 Sensor 2
P2271 trouble code definition O2 Sensor Signal Stuck Rich Bank 1 Sensor 2 What the P2271 code means This code indicates the...
P3414 OBD-II Trouble Code: Cylinder 2 Exhaust Valve Control Performance
P3414 means a problem in cylinder 2 with the exhaust valve was detected due to a faulty O2 sensor, bad camshaft timing, or a cracked or loose gas cap.

Related questions

Flashing green light next to "D" and check engine light on.
For this particular issue, I would start by checking the continuity of the cruise control switch (https://www.yourmechanic.com/services/cruise-control-switch-replacement) buttons. You will need to check these with a volt meter to determine if they are getting power. If you need assistance with...
Engine check light, rough idle, loss of power.
Hello. If your filter is over oiled and the oil got onto the hot wire of the air flow sensor (https://www.yourmechanic.com/services/mass-airflow-sensor-replacement), then that can cause it to burn out. A scan tool could be used to check the reading of...
Knocking noise coming from the crankshaft
The cylinder heads are one part of the complete engine package. As such, when they are rebuilt, other critical components such as connecting rods, bearings, pistons and cylinder sleeves are not replaced. If your head gasket broke, causing water to...

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 (855) 347-2779 · hi@yourmechanic.com