What Does P1748 Mean?
The torque converter clutch (TCC) solenoid has failed in the energized (on) position, causing the clutch to remain engaged when it shouldn't. This results in rough idle, stalling at stops, and poor driveability at low speeds.
Common Causes
45%
Failed TCC solenoid valve stuck closed/energized internally
25%
Shorted wiring harness or connector to TCC solenoid
20%
Failed transmission control module (TCM/PCM) output driver
10%
Mechanical binding in torque converter clutch mechanism
Diagnostic Steps
1
Step 1: Inspect transmission fluid condition and level for contamination or debris
2
Step 2: Perform resistance test on TCC solenoid (typically 20-30 ohms) with harness disconnected
3
Step 3: Check for short to ground in wiring harness between TCM and solenoid using multimeter
4
Step 4: Monitor TCC solenoid command vs actual status using bidirectional scan tool controls
5
Step 5: Road test vehicle monitoring TCC slip RPM and engagement behavior while observing live data
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
The torque converter clutch (TCC) solenoid has failed in the energized (on) position, causing the clutch to remain engaged when it shouldn't. This results in rough idle, stalling at stops, and poor driveability at low speeds.
The most common cause of P1748 (Torque Converter Clutch Solenoid Failied On) is: Failed TCC solenoid valve stuck closed/energized internally
Typical repair costs for P1748 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may stall when coming to a stop, creating a potential safety hazard in traffic. Continued driving may cause transmission overheating and clutch damage.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1748 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automatic Transmission
Difficulty
Type
Manufacturer
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