P1814: 4WD Low Indicator Circuit Open
The P1814 code indicates that the transmission control module (TCM) or powertrain control module (PCM) has detected an open circuit in the 4WD Low indicator circuit. This circuit typically includes a switch or sensor that signals the module when the driver selects 4WD Low range, along with the associated wiring and the dashboard indicator light. An open circuit means there is an electrical break that prevents the module from detecting the 4WD Low status.
01. Most Common Causes
- Faulty or disconnected 4WD Low selector switch
- Damaged, corroded, or disconnected wiring between the switch and control module
- Burnt out or open 4WD Low indicator bulb
- Corroded or bent pins in the transfer case switch connector
- Internal failure in the PCM or TCM that monitors the circuit
- Issue in the transfer case control module (if applicable)
02. Symptoms You Will Notice
- 4WD Low indicator light on the dashboard stays off or does not illuminate when selected
- Inability to engage or disengage 4WD Low mode
03. Step-by-Step Diagnosis
Use a scan tool to confirm the P1814 code and check for related codes.
Visually inspect the 4WD Low selector switch and its connector for damage, corrosion, or loose connections.
Test the switch for continuity and proper operation using a multimeter.
Check the wiring harness between the switch and the PCM/TCM for opens, shorts, or corrosion.
Inspect the 4WD Low indicator bulb and replace if burned out.
If all else is normal, test the PCM/TCM for internal faults or perform a module reprogramming.
1. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive with this code, but 4WD Low may not engage or disengage properly. Avoid off-road or low-traction situations until repaired.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on the cause. A simple switch replacement may cost around $100-$200, while wiring repairs or module replacement can be higher.