P0905Generic code

P0905 Code: Gate Select Position Circuit Range/Performance

The P0905 code means the gate select position sensor gives a reading that is electrically valid but does not match what the computer expects. The main effect is that the transmission does not know where its mechanism is. Compare the sensor reading against the real position to find the fault.

Severity
High
Can I keep driving?
Yes, but with caution
Estimated cost
$60 to $800
Difficulty
Medium
System
Transmission
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P0905 code means

Automated manual transmissions (Opel Easytronic, Fiat Dualogic, Toyota MMT, BMW SMG, Ford Durashift, Volkswagen ASG) and many dual clutch transmissions use electric or hydraulic actuators to disengage the clutch, to choose the gear plane (select) and to engage the gear (shift). The transmission computer watches every actuator with position sensors. The select sensor reports which plane the mechanism is in.

The sensor gets a 5 volt reference and a ground from the computer and sends back a signal between about 0.5 and 4.5 volts. The P0905 code is a range fault, which means the sensor is measuring but measuring wrong, or that a real abnormal condition exists.

If its signal fails, the computer does not know which plane is selected and blocks the shifts. After any repair of these components you must run the transmission relearn procedures with a scan tool (clutch touch point, select and shift positions). Without them the transmission will not work properly.

This kind of fault is not usually solved with a multimeter, because electrically everything looks correct. You have to compare what the part reports with reality: use a pressure gauge, a thermometer or a tachometer, or command the component with the scan tool and watch whether the physical result matches the order.

P0905 code symptoms

  • Check engine light on.
  • The transmission does not recognize the position of its mechanism.
  • The transmission does not go into gear or stays in neutral.

Likely causes of the P0905 code

  1. Degraded or out-of-calibration sensor. It gives believable but wrong readings.
  2. Real abnormal condition. The system is actually working outside normal limits.
  3. High resistance in the connector from corrosion, which shifts the reading.
  4. Damaged or clogged port, hose or tone wheel, depending on the type of sensor.

How to diagnose the P0905 code step by step

  1. Read the sensor value on the scan tool and compare it with what you expect.
  2. Inspect the connector for corrosion, water or loose pins.
  3. Check supply and ground with the key on: the reference should be correct and the ground voltage drop under 0.1 volts.
  4. Measure the signal with the connector attached and see whether it changes with the condition.
  5. Do a wiring wiggle test with the scan tool in graphing mode.
  6. Check the continuity of each wire to the computer (under 1 ohm).
  7. Run the transmission relearn procedures after the repair.

How to fix the P0905 code

  • Repair the connector or the wiring.
  • Replace the sensor if the tests confirm it is bad.
  • Correct the real condition if one exists.
  • Clear the codes and verify with a road test.

Technical reference data

  • 5 volt reference, ground and a signal of 0.5 to 4.5 volts (or a contactless Hall effect sensor).
  • Approximate values only: check the manufacturer data for your vehicle.

Brand-specific notes

This code is very common on automated manual transmissions. On many hydraulic systems the actuator fluid is a specific type and the reservoir should be checked regularly.

P0905 on Opel

Very common on the Opel Easytronic.

P0905 on Fiat

Very common on the Fiat Dualogic.

P0905 on Toyota

Very common on the Toyota MMT.

P0905 on Smart

Seen on Smart vehicles with an automated manual transmission.

P0905 on BMW

Very common on the BMW SMG.

Frequently asked questions about P0905

Can I drive with a P0905 code?
With caution. The transmission can be left without gears.
Do I have to replace the sensor?
Only if the tests confirm it. The connector and the wiring fail just as often as the sensor does.
What does the gate select position sensor do?
Automated manual transmissions (Opel Easytronic, Fiat Dualogic, Toyota MMT, BMW SMG, Ford Durashift, Volkswagen ASG) and many dual clutch units use electric or hydraulic actuators to release the clutch, select the gear plane and engage the gear. The computer watches each actuator with position sensors. The select sensor reports which plane the mechanism is in.
How much does it cost to fix P0905?
As a rough guide, between $60 and $800. A connector cleanup is at the low end, and a new sensor with the relearn procedures costs more.
What does the P0905 code mean?
The P0905 code is a generic OBD2 code that means the gate select position sensor gives an implausible reading, one that is electrically valid but does not match what the computer expects.
Will a P0905 code clear itself?
Not usually. A drifting sensor or a corroded connector keeps giving bad readings, so the code returns.
What is the most common cause of P0905?
A degraded or out-of-calibration sensor, or high resistance in a corroded connector that shifts the reading.

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