P0860Generic code

P0860 Code: Gear Shift Module Communication Circuit

The P0860 code means the transmission computer has lost communication with the gear shift module. The transmission may go into limp mode, or the shifter may stop responding. Damaged wiring or a module without power is the usual cause.

Severity
High
Can I keep driving?
Yes, but with caution
Estimated cost
$20 to $900
Difficulty
Medium
System
Transmission
Applies to
All OBD2 vehicles
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What the P0860 code means

Some vehicles have a dedicated communication line to the gear shift module, in addition to the general CAN network. The shifter position, the shift commands and the transmission status travel over it.

The P0860 code is stored when that communication fails. The transmission then does not receive or send essential information and activates limp mode. Check power and ground at both modules and the wiring between them. If other U codes are stored, resolve them first.

Always start with the simplest things: fuse, relay and connector. Then check power, ground and signal with the component plugged in (using back-probes), and finally the continuity of each wire to the computer. Only replace a module when everything else checks out.

P0860 code symptoms

  • Transmission in limp mode.
  • The shifter does not respond or the gear indicator does not work.
  • Check engine light on.

Likely causes of the P0860 code

  1. Damaged communication wiring, either cut or shorted.
  2. Power or ground problem at one of the modules. A module with no power cannot communicate.
  3. Corroded connector, which raises the resistance of the line.
  4. Shifter module or transmission module with an internal fault.

How to diagnose the P0860 code step by step

  1. Check power and ground at both modules.
  2. Test the communication line for continuity and for the absence of shorts.
  3. Read related U codes.

How to fix the P0860 code

  • Repair the wiring or the connector.
  • Replace the faulty module.

Technical reference data

  • Dedicated communication line or CAN network, depending on the vehicle.
  • Reference values are only a guide, so look up the manufacturer data for your vehicle.

Brand-specific notes

On vehicles with an electronic shifter, the shifter module is the first suspect when you see a P0860 code.

P0860 on BMW

On BMW vehicles with an electronic shifter, the shifter module is the first suspect.

P0860 on Mercedes

On Mercedes vehicles with an electronic shifter, the shifter module is the first suspect.

P0860 on Jeep

On Jeep vehicles with an electronic shifter, the shifter module is the first suspect.

P0860 on Ford

On Ford vehicles with an electronic shifter, the shifter module is the first suspect.

Frequently asked questions about P0860

Can I drive with a P0860 code?
With caution. The transmission may go into limp mode, and the shifter may not respond, so get it checked soon.
What usually fails?
The wiring or one of the modules.
Does a new module need to be programmed?
Many times, yes.
How much does it cost to fix P0860?
Between $20 and $900, from a simple wiring repair up to replacing a module.
What does the P0860 code mean?
It is a generic OBD2 code that means communication with the gear shift module has failed.

Questions about the P0860 code

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