Definition of Code P0860
Code P0860 is a generic powertrain code related to the transmission, including pressure faults and sensor failures. In this case, the Engine Control Module (ECM) has detected a fault in the shift module communication circuit.
What Does Code P0860 Mean
A P0860 code will be stored when the ECM has found a fault or error in the shift module communication circuit.
Note, the P0860 code will only apply to vehicles equipped with an electronic traction control system.
The shift module communication circuit sends information via the vehicle’s control network (CAN) to the ECM, in addition to other controllers, to help calculate the vehicle’s efficient operation. The CAN is a communication bus that helps different vehicle modules communicate with each other. The shift module helps the vehicle determine the correct shift timing.
What Causes Code P0860?
Several issues can cause a P0860 code, including:
Damaged, open, or short-circuited wiring or connectors and related components
Damaged or faulty manual lever position sensor
Excessive moisture levels in the shift module sensor connector
What Are the Symptoms of Code P0860?
Symptoms of a P0860 code may include:
- Check engine or warning light may illuminate
- Traction control malfunction light may flash or stay on
- Reduced fuel economy
- The vehicle may lack traction in slippery road conditions
- The vehicle may shift roughly
- The vehicle may not shift into gear or out of gear
- The vehicle may enter “limp” mode
How Does a Mechanic Diagnose Code P0860?
A mechanic can use several methods to diagnose a P0860 fault code, including:
Using an OBD-II scanner to check for a stored P0860 fault code
Visually inspecting all wiring and connectors related to the shift module for possible damage or corrosion
Using a specialized tool (such as an Autohex) to help locate the error or malfunction
Using a memory saver device to store the memory of other modules during reprogramming
Using a diagnostic CAN scanner to view pin values and operating control modules
Testing the ground circuits of the control module for continuity with the battery ground
Checking for loose or corroded electrical connectors that could increase circuit resistance
Common Mistakes When Diagnosing Code P0860
Sometimes the shift module is incorrectly identified as the cause of the P0860 code, when the actual problem is in the electrical wiring or with a switch or sensor. It is recommended to fully diagnose any error or fault code before performing repairs.
How Severe Is Code P0860?
Since safely operating a vehicle will most likely be affected due to faults that store a P0860 code, this code is considered a potentially serious one. When this code appears, it is recommended to bring your vehicle to your local service center or a mechanic immediately for repair and diagnosis.
What Repairs Can Fix Code P0860?
Several repairs can correct a P0860 fault code and include:
Repairing any damaged, open, or corroded wiring, connectors, and related components
Replacing the damaged or faulty shift lever
Replacing the damaged or faulty shift module
Clearing all codes, testing the vehicle, and rescanning to see if any codes reappear