P1868 Transfer Case Contact Plate Power Open
Diagnostic trouble code P1868 indicates an open circuit in the power supply to the transfer case contact plate. This electromechanical component provides electrical communication between the transmission control module (TCM) and the rotating parts of the transfer case, typically in electronically controlled four-wheel-drive systems. An open circuit prevents the contact plate from functioning properly, which can affect transfer case position detection and 4x4 mode control.
01. Most Common Causes
- Damaged or worn transfer case contact plate
- Broken or corroded wiring in the power supply circuit
- Loose or corroded connector at the contact plate
- Blown fuse for the transfer case circuit
- Internal voltage supply failure in the transmission control module (TCM)
- Poor or corroded ground points in the circuit
02. Symptoms You Will Notice
- Check Engine Light or 4WD warning light illuminated
- Inability to shift into or out of four-wheel drive
- Erratic or no response from the 4WD system
- Transmission or transfer case stuck in a single mode
03. Step-by-Step Diagnosis
Scan for codes and verify P1868 is present
Inspect the transfer case contact plate and its connector for damage, corrosion, or loose pins
Check the power supply circuit wiring for breaks, shorts, or corrosion
Test the fuse for the transfer case circuit and replace if blown
Measure voltage at the contact plate connector with key on; if no voltage, trace back to TCM
Check ground connections for corrosion or looseness
If all else is good, suspect a faulty TCM and perform further module testing
1. Frequently Asked Questions
Is it safe to drive?▼
You can drive short distances in 2WD, but avoid off-road or demanding conditions. The 4WD system may not engage properly, which could be unsafe in slippery terrain. Have it diagnosed soon.
How much does it cost to fix?▼
Repair costs range from $100 to $500, depending on the cause. A simple fuse or wiring repair may be under $150, while replacing the contact plate or TCM can exceed $400.