P2749

Intermediate Shaft Speed Sensor C Circuit

Q: Is it safe to drive with P2749?

You can usually drive to a shop, but shifts may be harsh or unpredictable. Avoid long trips until it's fixed to reduce transmission wear.

Q: Can I just clear P2749?

It returns until the sensor or its wiring is repaired.

Transmission controls Generic OBD-II Medium

What it means

P2749 sets when the intermediate shaft speed sensor C circuit has a fault. The transmission controller uses this speed signal to time shifts and torque-converter lockup, so a lost or erratic signal can cause harsh or wrong shifts, wrong-gear-ratio codes, and failsafe mode. The engine starts and runs normally.

Medium

Can I keep driving? Often yes but shifting may be erratic — losing a transmission speed signal can trigger harsh shifts or failsafe mode. Get it checked soon.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Harsh, erratic, or incorrect gear shifts
Transmission entering failsafe/limp mode
Possible gear-ratio or speedometer-related codes

Common causes

Most likely first

Faulty intermediate shaft speed sensorLikely
Open, shorted, or corroded sensor wiring or connectorCommon
Poor electrical connection at the sensorCommon
Metal debris or damage at the sensor tip or tone ringLess often
Faulty TCM/PCM (least likely)Less often

How to diagnose & fix

Work through it in order

Scan for related codes (P2748, P2750, P2751) and read freeze-frame.
Inspect the speed sensor connector and wiring for damage or corrosion.
Check the sensor and its mounting for debris or damage.
Measure the sensor's output or resistance against spec.
Replace the speed sensor if faulty; verify wiring and the module last.

FAQ

Quick answers

Is it safe to drive with P2749?+

You can usually drive to a shop, but shifts may be harsh or unpredictable. Avoid long trips until it's fixed to reduce transmission wear.

Can I just clear P2749?+

It returns until the sensor or its wiring is repaired.

Read & clear P2749 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX