The intermediate shaft speed sensor is not reporting correctly, which upsets shift timing on a modern multi-speed automatic or DSG.
P0791 — also written PO791, P 0791, 0791 — is the OBD-II code for intermediate shaft speed sensor circuit. Same code, same fix: this page covers every spelling of it.
P0791 is a transmission fault code, typically costing £180–£1600 to put right in a UK garage.
What causes P0791?
- Failed speed sensor
- Mechatronic unit fault on DSG boxes
- Wiring or connector damage
- Low fluid level
How P0791 is fixed
- Read the gearbox module for related codes
- Replace the sensor where separately serviceable
- Mechatronic repair or replacement on DSG
P0791 repair cost in the UK
Most P0791 repairs land between £180–£1600 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Can you drive with P0791?
Expect limp mode with a fixed gear. Recover if speed is severely limited.
Urgency: high.