P0791 Intermediate Shaft Speed Sensor Circuit

OBD2 Code: P0791

Description: Intermediate Shaft Speed Sensor Circuit

Definition: This code indicates a problem with the intermediate shaft speed sensor circuit, which is responsible for monitoring the rotational speed of the intermediate shaft in the transmission. The data from this sensor is used by the vehicle’s powertrain control module (PCM) to ensure proper transmission operation and shift timing.

P0791 – Intermediate Shaft Speed Sensor Circuit

Typical severity: Moderate

Common Causes

P0791 – Intermediate Shaft Speed Sensor Circuit

Common Causes:

• Faulty intermediate shaft speed sensor
• Wiring issues such as frayed wires or poor connections
• Low transmission fluid level
• Internal transmission problems

Common Misdiagnosis

OBD2 Code: P0791

Description: Intermediate Shaft Speed Sensor Circuit

Common Misdiagnosis: Replacing the speed sensor without checking for wiring issues or connector problems.

Common Diagnostic Steps

OBD2 Code: P0791

Description: Intermediate Shaft Speed Sensor Circuit

• Check the vehicle’s service manual for specific diagnostic procedures related to the intermediate shaft speed sensor circuit.
• Inspect the wiring and connectors associated with the intermediate shaft speed sensor for any signs of damage, corrosion, or disconnection.
• Use a multimeter to test the voltage and ground signals at the sensor connector to ensure they are within manufacturer specifications.
• Verify that there is continuity in the wiring between the sensor and the powertrain control module (PCM).
• If equipped, use an OBD2 scanner to monitor live data from the intermediate shaft speed sensor while driving to check for erratic readings.
• Test or replace the intermediate shaft speed sensor if it is found to be faulty or out of specification.
• If all tests pass but code persists, consider checking for PCM updates or reprogramming as per manufacturer guidelines.