P2746 — Intermediate Shaft Speed Sensor “B” Circuit Range/Performance #

Please note: The exact description of this code may vary depending on the vehicle manufacturer (OEM). Below are known variations:

• Toyota/Lexus: Intermediate Shaft Speed Sensor “B” Circuit Range/Performance
• Honda/Acura: Intermediate Shaft Speed Sensor “B” Range/Performance
• GM: Intermediate Shaft Speed Sensor “B” Performance
• Ford: Intermediate Shaft Speed Sensor “B” Circuit Range/Performance

Code P2746 Summary #

P2746 relates to the Intermediate Shaft Speed Sensor “B” within an automatic transmission system. The vehicle’s Powertrain Control Module (PCM) or Transmission Control Module (TCM) uses this sensor to monitor rotational speed of a specific shaft, ensuring smooth gear shifts and optimal performance. When the PCM/TCM detects that the sensor’s signal is outside the expected range or inconsistent with other data, it triggers this code. Accurate sensor data is crucial for transmission operation, so this fault can lead to drivability concerns. While not immediately catastrophic, ignoring P2746 can cause further transmission issues over time.

Common Symptoms for Trouble Code P2746 #

A faulty intermediate shaft speed sensor or its circuit can trigger a range of symptoms. Most often, drivers notice issues related to shifting or transmission response. These symptoms may appear sporadically or persistently, depending on the nature of the fault.

• Check Engine Light (CEL) illuminated
• Transmission stuck in limp mode (restricted to one or two gears)
• Harsh, delayed, or erratic shifting
• Reduced fuel efficiency
• Possible speedometer irregularities (rare, but possible if sensor data is shared)
• Transmission warning light (on vehicles equipped with a dedicated indicator)

Probable Causes for Code P2746 #

Several potential issues can cause the P2746 code. Some are more common than others, and the order below reflects the usual frequency based on field experience and OEM data.

1. Faulty intermediate shaft speed sensor “B” (sensor itself has failed or degraded)
2. Damaged, corroded, or loose electrical connectors at the sensor or harness
3. Open or shorted wiring between the sensor and the PCM/TCM
4. Internal transmission problems (excessive wear or mechanical failure affecting shaft speed)
5. PCM/TCM software glitches (rare, but possible if all hardware checks out)

Step-by-Step Diagnostic for P2746 #

Diagnosing this code requires a systematic approach, starting from the easiest checks and moving towards more complex inspections. Having a scan tool, a digital multimeter, and access to OEM wiring diagrams is highly recommended.

• Step 1: Record freeze frame data and all stored codes with a scan tool. Clear codes and see if P2746 returns after a test drive.
• Step 2: Visually inspect the intermediate shaft speed sensor “B”, its connector, and wiring harness for damage, corrosion, or disconnection.
• Step 3: Check sensor output with a scan tool. Compare readings to manufacturer specs and to other shaft speed sensors if possible.
• Step 4: Test circuit continuity and resistance with a multimeter from sensor to PCM/TCM. Look for open or short circuits.
• Step 5: If wiring and sensor test good, inspect internal transmission components as per OEM guidelines. Look for excessive wear or slippage.
• Step 6: In rare cases, reflash or update PCM/TCM software if instructed by OEM service bulletins.

Possible Repairs for P2746 #

The correct repair depends on the cause identified during diagnosis. Addressing the root issue is essential for reliable operation.

• Replace faulty intermediate shaft speed sensor “B”
• Repair or replace damaged connectors or corroded terminals
• Repair or replace damaged wiring in the sensor circuit
• Repair or overhaul internal transmission components (if mechanical failure is found)
• Update or reprogram PCM/TCM software (only if OEM recommends and all hardware checks out)

Is It Safe to Drive with Code P2746? #

Limited driving is possible, but not recommended for extended periods. While P2746 rarely causes immediate transmission failure, it often triggers limp mode or erratic shifting, which can compromise vehicle control and safety. Continued driving may also worsen internal transmission wear or cause further damage. It’s best to have the issue diagnosed and repaired as soon as possible.

Vehicles Most Commonly Affected by P2746 #

This code appears most frequently on vehicles with complex electronically controlled transmissions, particularly those from the following manufacturers:

• Toyota/Lexus (especially models with U-series and Aisin transmissions)
• Honda/Acura (select models with electronically controlled automatics)
• General Motors (GM) (vehicles with 6-speed and 8-speed automatics)
• Ford/Lincoln (certain models with advanced automatic transmissions)

Common Mistakes & Best Practices for P2746 #

Avoiding misdiagnosis and unnecessary repairs is key. Here are the most frequent errors and how to steer clear of them:

• Replacing the sensor without checking wiring or connectors first
• Overlooking corroded or loose electrical terminals
• Ignoring OEM diagnostic flowcharts and TSBs (Technical Service Bulletins)
• Assuming the problem is only electrical—mechanical faults can trigger this code, too
• Not clearing codes after repair and confirming with a road test

Quick FAQ for P2746 #

What is an intermediate shaft speed sensor?
This sensor monitors the rotational speed of a transmission shaft located between the input and output, providing vital data for shift timing and torque management.

Can a bad speed sensor cause transmission slipping?
Yes, if the sensor sends incorrect data or fails, the TCM/PCM may command erratic shifts or limp mode, which can feel like slipping or delayed engagement.