P2748: Intermediate Shaft Speed Sensor B Circuit Intermittent
The P2748 code indicates an intermittent signal from the intermediate shaft speed sensor B, which monitors the rotational speed of the intermediate shaft in the transmission. This sensor is critical for proper transmission shift timing and torque converter lockup. An intermittent circuit issue can cause erratic transmission behavior, including harsh shifting, slipping, or failure to shift. The problem may stem from a faulty sensor, damaged wiring, or a poor electrical connection.
01. Most Common Causes
- Faulty intermediate shaft speed sensor B
- Damaged or corroded wiring/connectors
- Intermittent electrical connection
- Transmission fluid contamination affecting sensor
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission slipping or delayed engagement
- Reduced fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect sensor B wiring and connector for damage, corrosion, or loose pins.
Step 3: Test sensor resistance and compare to manufacturer specs (typically 200-900 ohms).
Step 4: Check for intermittent signal by wiggling wiring harness while monitoring sensor output with a multimeter or oscilloscope.
Step 5: If wiring and sensor are OK, inspect transmission control module (TCM) for faults or software updates.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as intermittent sensor signals can cause unpredictable transmission behavior, potentially leading to transmission damage or unsafe driving conditions.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a DIY sensor replacement, or $150 to $400 if professional labor is required, depending on vehicle make and model.