What Does P1860 Mean?
This code indicates either a torque converter clutch PWM solenoid circuit fault OR a short to battery voltage in the transfer case contact plate 'D' circuit. The circuit is receiving unintended voltage from the battery positive supply.
Common Causes
35%
Wiring harness chafed against metal causing short to power
25%
Failed contact plate or internal transmission short to power supply
20%
Damaged connector allowing pins to contact power supply circuits
15%
Failed TCC solenoid with internal short to power
5%
TCM internal driver circuit failure creating false voltage
Diagnostic Steps
1
Step 1: Disconnect transmission/transfer case connector and check for voltage on contact plate 'D' circuit pin with key on
2
Step 2: If voltage present at connector, trace harness for damage and shorts to battery voltage
3
Step 3: Check for proper insulation on all wiring, especially near heat sources or sharp edges
4
Step 4: Test TCC solenoid resistance and verify no short to power internally
5
Step 5: If external circuit is good, inspect internal contact plate for shorts to power supply
Estimated Repair Cost
$150 - $1,100
Parts + labor, varies by vehicle and location
This code indicates either a torque converter clutch PWM solenoid circuit fault OR a short to battery voltage in the transfer case contact plate 'D' circuit. The circuit is receiving unintended voltage from the battery positive supply.
The most common cause of P1860 (TCC PWM Solenoid Circuit Electrical/ Transmission Transfer Case Contact Plate 'D' Short Circuit To Battery) is: Wiring harness chafed against metal causing short to power
Typical repair costs for P1860 range from $150 to $1,100, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May cause harsh shifting, torque converter lock-up issues, or transmission overheating. Could result in unexpected vehicle acceleration or deceleration behavior.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1860 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission/Transfer Case Control
Difficulty
Type
Manufacturer
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