P0791moderate severityPowertrain
Intermediate Shaft Speed Sensor Circuit
on 2011 Audi Q7 3.0L Supercharged V6 · AWD
What this code means
The intermediate shaft speed sensor signal is out of range or missing. This affects the transmission's ability to accurately time shifts.
Symptoms
- Harsh or erratic shifting
- Transmission warning light on
- Speedometer may read incorrectly
Common causes
- Faulty intermediate shaft speed sensor
- Damaged sensor wiring or connector
- Metal debris on sensor tip
- Faulty transmission control module
Diagnostic steps
- Scan for related transmission codes
- Inspect sensor connector and wiring
- Check sensor resistance against spec
- Test signal output with scope while driving
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