P0860
Gear Shift Module Communication Circuit
About P0860
The P0860 code indicates an gear shift module communication circuit fault has been detected in the vehicle's electrical system. This code relates to the internal control module, charging system, or starter circuit. Electrical issues at the PCM level can cause widespread vehicle operation problems and should be diagnosed thoroughly. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.
Here are the key things to understand: Intermittent electrical failures. Check Engine Light (MIL) illuminated. Multiple warning lights on dashboard. Erratic gauge readings. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.
The most common reasons this occurs include: Faulty engine control module (ECM/PCM). Corroded or damaged wiring connectors. Water damage to electrical connectors. Failed relay or fuse. Identifying the root cause is the first step toward finding the right solution.
To resolve this, follow these recommended steps: Connect an OBD-II scanner and read all stored trouble codes and freeze frame data. Check battery voltage and charging system output with a multimeter. Inspect wiring and connectors related to the trouble code. Test circuit voltage, ground, and resistance with a multimeter. Check related fuses and relays. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.
This article is part of our Powertrain (P) collection on OBD Codes. We provide comprehensive, up-to-date information to help you find solutions quickly.
Quick Answer
Are electrical codes hard to diagnose?
Electrical codes can be challenging because they often involve intermittent issues. A thorough inspection of wiring, connectors, and grounds with a multimeter is essential for accurate diagnosis.
Overview
The P0860 code indicates an gear shift module communication circuit fault has been detected in the vehicle's electrical system. This code relates to the internal control module, charging system, or starter circuit. Electrical issues at the PCM level can cause widespread vehicle operation problems and should be diagnosed thoroughly.
Symptoms
- Intermittent electrical failures
- Check Engine Light (MIL) illuminated
- Multiple warning lights on dashboard
- Erratic gauge readings
Common Causes
- Faulty engine control module (ECM/PCM)
- Corroded or damaged wiring connectors
- Water damage to electrical connectors
- Failed relay or fuse
Diagnosis Steps
- 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
- 2Check battery voltage and charging system output with a multimeter
- 3Inspect wiring and connectors related to the trouble code
- 4Test circuit voltage, ground, and resistance with a multimeter
- 5Check related fuses and relays
Estimated Repair Cost
Cost varies by vehicle, location, and repair shop. Includes parts and labor.