What Does P0908 Mean?
The TCM has detected intermittent signal dropouts or erratic behavior in the gate select position sensor circuit. The sensor signal sporadically falls outside expected parameters before returning to normal, indicating a loose connection, damaged wire, or sensor that is failing under vibration or temperature changes.
Common Causes
35%
Loose or corroded connector at the gate select position sensor
30%
Intermittent break in wiring harness due to vibration fatigue
25%
Gate select position sensor failing intermittently under heat or vibration
10%
Poor TCM connector pin contact causing intermittent signal loss
Diagnostic Steps
1
Step 1: Monitor the gate select position sensor signal on a scan tool graphing function while tapping on the sensor and wiggling the connector — watch for signal dropouts or spikes.
2
Step 2: Perform a thorough inspection of the connector terminals at both the sensor and TCM ends — look for spread terminals, corrosion, or green verdigris on copper pins.
3
Step 3: Flex the wiring harness along its length while monitoring the signal — an intermittent break will cause a momentary signal change.
4
Step 4: Check for TSBs related to harness routing or connector seal upgrades for the specific vehicle platform.
5
Step 5: If the intermittent fault cannot be reproduced, inspect for water intrusion paths at the connector and apply dielectric grease; then road test under conditions that trigger the fault (heat, vibration, bumpy roads).
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
The TCM has detected intermittent signal dropouts or erratic behavior in the gate select position sensor circuit. The sensor signal sporadically falls outside expected parameters before returning to normal, indicating a loose connection, damaged wire, or sensor that is failing under vibration or tem...
The most common cause of P0908 (Gate Select Position Circuit Intermittent) is: Loose or corroded connector at the gate select position sensor
Typical repair costs for P0908 range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Intermittent signal loss can cause momentary shift hesitation or unexpected gear engagement. Drive with caution and avoid aggressive driving until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0908 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
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
