P2751: Intermediate Shaft Speed Sensor C Circuit No Signal
The P2751 code indicates that the Powertrain Control Module (PCM) has detected no signal from the intermediate shaft speed sensor C, 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. A loss of signal can result from a faulty sensor, damaged wiring, or connector issues, leading to erratic shifting or transmission malfunction.
1. Most Common Causes
- Faulty or worn intermediate shaft speed sensor 'C'
- Open or shorted wiring in the sensor circuit (to the PCM)
- Corroded, loose, or moisture-damaged sensor connector
- Damaged, displaced, or contaminated reluctor ring or exciter gear on the intermediate shaft
- Short to ground or reference voltage in the wiring harness
- Internal PCM failure (rare but possible)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Erratic or harsh shifting
- Transmission may go into limp mode
- Reduced fuel economy
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Visually inspect the sensor and wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's resistance and voltage with a multimeter per manufacturer specs.
Step 4: If sensor and wiring are okay, check the PCM for faults or update software.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the transmission may shift erratically or fail, potentially causing further damage.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts and labor, depending on the cause and vehicle model.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.