P1866
Transmission Transfer Case System Concern Servicing Required
P1866 is an OBD-II diagnostic trouble code meaning: Transmission Transfer Case System Concern Servicing Required. Common causes: low oil level in transfer case, problems with solenoid valves. Estimated repair cost: $17–89.
Symptoms
- Check Engine Light Is On
- Problems with switching all-wheel drive modes
- Unusual noises from the transfer case
- Reduced all-wheel drive efficiency
Causes
- Low oil level in transfer case
- Problems with solenoid valves
- Wear of mechanical components
- Errors in the operation of the electronic control module
- Wiring damage
How to Fix
- Check the level and condition of the oil in the transfer case
- Diagnose transfer case solenoid valves
- Check the condition of mechanical components
- Scan the electronic control module for errors
- Inspect the integrity of the wiring and contacts
Related codes
Error P1866 by Vehicle Brand
FAQ
What does the P1866 code mean?
P1866 is an OBD-II diagnostic trouble code that indicates: Transmission Transfer Case System Concern Servicing Required
What causes a P1866 error code?
The most common causes of P1866 include: Low oil level in transfer case; Problems with solenoid valves; Wear of mechanical components; Errors in the operation of the electronic control module.
How do I fix a P1866 diagnostic trouble code?
To fix P1866: Check the level and condition of the oil in the transfer case. Diagnose transfer case solenoid valves. Check the condition of mechanical components. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P1866?
Limited driving only, diagnose soon
How much does it cost to fix P1866?
The estimated repair cost for P1866 is $17–89. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat