What Does P0927 Mean?
The TCM has detected that the gear shift reverse actuator circuit voltage exceeds the expected range. This high voltage condition suggests a short to battery voltage in the wiring, an open ground circuit, or a stuck relay. The reverse actuator controls rearward shift motion for even-numbered gears and reverse in automated manual transmissions.
Safety Warning
A high circuit may cause continuous or unintended actuator operation, potentially engaging gears unexpectedly. Do not drive; tow the vehicle.
Common Causes
35%
Short to battery voltage in reverse actuator wiring harness
30%
Open ground circuit at reverse actuator
20%
Actuator relay stuck closed with welded contacts
15%
TCM output driver fault stuck high
Diagnostic Steps
1
Step 1: With key on and actuator not commanded, measure voltage at the actuator connector — should be 0V; battery voltage indicates short to power or stuck relay.
2
Step 2: Verify ground continuity from actuator ground pin to chassis ground — should be less than 1 ohm; open ground causes the signal to float high.
3
Step 3: Disconnect the actuator and recheck voltage — persistence indicates harness or relay fault; voltage drop indicates actuator internal fault.
4
Step 4: Inspect harness routing for chafing against power supply wires near the transmission and engine bay.
5
Step 5: Remove and test the actuator relay (if equipped) — check for welded contacts with an ohmmeter.
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
The TCM has detected that the gear shift reverse actuator circuit voltage exceeds the expected range. This high voltage condition suggests a short to battery voltage in the wiring, an open ground circuit, or a stuck relay. The reverse actuator controls rearward shift motion for even-numbered gears a...
The most common cause of P0927 (Gear Shift Reverse Actuator Circuit High) is: Short to battery voltage in reverse actuator wiring harness
Typical repair costs for P0927 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A high circuit may cause continuous or unintended actuator operation, potentially engaging gears unexpectedly. Do not drive; tow the vehicle.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0927 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automated Manual Transmission (Shift Control)
Difficulty
Type
Generic (SAE)
Recommended Tools
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