P0794 - Intermediate Shaft Speed Sensor A Circuit Intermittent
The P0794 code indicates that the powertrain control module (PCM) has detected an intermittent signal from the intermediate shaft speed sensor 'A'. This sensor monitors the rotational speed of the intermediate shaft within the transmission, which is crucial for proper shift timing and torque converter lockup. An intermittent circuit issue can cause erratic transmission behavior, including harsh or delayed shifts, and may trigger limp mode. Common causes include a faulty sensor, damaged wiring or connectors, or internal transmission problems.
01. Most Common Causes
- Faulty intermediate shaft speed sensor
- Damaged or corroded wiring/connectors
- Intermittent electrical connection
- Transmission fluid contamination or low fluid level
- Internal transmission mechanical failure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or delayed gear shifts
- Transmission slipping or erratic shifting
- Reduced fuel economy
- Transmission stuck in limp mode
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Inspect the intermediate shaft speed sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test sensor resistance and signal output with a multimeter or oscilloscope.
Step 4: Check transmission fluid level and condition; top off or replace if necessary.
Step 5: If sensor and wiring are okay, perform a transmission system test to rule out internal failure.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as it can cause erratic shifting and potential transmission damage. If the transmission enters limp mode, you may lose high gears. Have it diagnosed promptly.
How much does it cost to fix?▼
The cost to fix P0794 typically ranges from $50 to $150 for sensor replacement and wiring repair, but can be higher if internal transmission work is needed.