Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected a problem with a sensor that helps it figure out how fast part of the transmission is spinning. It's like trying to ride a bike with a broken speedometer.
The P0791 code is triggered when the powertrain control module (PCM) detects a malfunction in the intermediate shaft speed sensor circuit.
The intermediate shaft speed sensor monitors the rotational speed of the transmission's intermediate shaft. This information is crucial for the PCM to adjust shift timing and transmission operation. A fault in this sensor or its circuit can lead to improper transmission performance.
• Check Engine Light is on
• Transmission shifting issues
• Poor fuel economy
• Faulty intermediate shaft speed sensor
• Damaged or corroded wiring/connectors
• Malfunctioning PCM
PCM: Powertrain Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Scan the vehicle for codes and freeze frame data
• Inspect the wiring and connectors for damage or corrosion
• Test the intermediate shaft speed sensor for proper operation
• Replace the intermediate shaft speed sensor
• Repair or replace damaged wiring/connectors
• Reprogram or replace the PCM if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular maintenance checks
• Ensure proper transmission fluid levels
• Inspect wiring for wear and tear
Sensor Issue
• Avoid driving at high speeds until repaired
• Get the vehicle inspected by a professional mechanic
Check with your vehicle manufacturer for warranty coverage on transmission components.
This code has been reported in vehicles with high mileage or those that have experienced transmission issues.
Moderate – It should be addressed soon to prevent further transmission damage.
Ignoring this code may lead to further damage and potentially unsafe driving conditions.
• Engine running
• Vehicle in motion
The intermediate shaft speed sensor is typically located on the transmission, near the intermediate shaft.
Q: Can I drive with a P0791 code?
A: It's not recommended to drive for extended periods with this code as it may cause further transmission damage.
Q: How do I reset the P0791 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is fixed, the code should not return.
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