P0959: Auto Shift Manual Mode Circuit Intermittent
What to do
The gearbox may switch between manual and automatic on its own. Harmless, though unsettling. Mention any drink ever spilled near the selector, since dried residue becomes conductive and causes exactly this.
What this code means
The manual mode circuit behaves inconsistently, so the transmission drops in and out of manual mode without being asked. Mid-journey that is disconcerting — the gearbox stops changing up, then starts again — but it threatens nothing, and a liquid spill into a console-mounted selector is the cause worth asking about however long ago it happened.
Likely causes
Start here
- Liquid spilled into the gear selector · moderate
- Corroded or loose connector · easy
- Faulty transmission mode switch · easy
Less common
- Damaged wiring under the centre console · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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