P0912 moderate

Gate Select Actuator Circuit Low

The P0912 code means the vehicle's onboard diagnostic system has detected: Gate Select Actuator Circuit Low. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$200 - $1,200 (parts and labor)
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Common Symptoms

  • Check Engine Light illuminated
  • Transmission cannot reach certain gear gates
  • Gear selection limited to one or two gears
  • Slow or incomplete gate selection movements

Probable Causes (Ranked by Likelihood)

  • Short to ground in gate select actuator circuit Very High
  • Faulty actuator motor with low current output High
  • Water intrusion at actuator connector Moderate
  • TCM output circuit fault Low

Step-by-Step Diagnostic Procedure

  1. Measure voltage at the gate select actuator connector

  2. Check for short to ground in the actuator wiring

  3. Inspect connector for moisture and corrosion

  4. Test actuator motor resistance

Frequently Asked Questions

What causes the gate select circuit to read low?

A short to ground in the wiring or a failed actuator motor can pull the circuit voltage below the expected minimum, triggering P0912.

Can I still select gears manually?

Automated manual transmissions do not have a manual override for the actuator. If the actuator cannot select gates, you are limited to whatever gear is currently engaged.

Is this a common failure on Smart cars?

Yes, the Smart ForTwo with its automated manual transmission is known for gate select actuator issues. Regular clutch and actuator maintenance helps prevent failures.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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