TCM Communication Circuit Range/Performance
The P0864 code means the vehicle's onboard diagnostic system has detected: TCM Communication Circuit Range/Performance. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $200 - $1,500 (parts and labor)
Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.
Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.
Affiliate links — we earn a commission at no extra cost to you.
What Are the Symptoms of P0864?
- Check Engine Light illuminated
- Intermittent transmission malfunctions
- Occasional limp mode activation
- Delayed or erratic response to shift commands
What Causes P0864? (Most Likely First)
- Degraded CAN bus wiring causing intermittent communication Very High
- TCM internal communication issue High
- Electromagnetic interference on CAN bus Moderate
- Aftermarket electronics interfering with CAN bus Low
Can I Still Drive with P0864?
Short distances only. P0864 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
Can aftermarket electronics cause P0864?
Yes, aftermarket devices tapped into the CAN bus (such as remote starters, performance tuners, or tracking devices) can introduce noise or bus loading that degrades communication quality.
What does range/performance mean for TCM communication?
It means the TCM is communicating, but the data quality or timing does not meet specifications. Messages may be delayed, corrupted, or missing intermittently.
Should I remove aftermarket accessories first?
Yes, disconnect any aftermarket devices connected to the CAN bus and clear the code. If P0864 does not return, the aftermarket device was the cause.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0864?
-
Monitor CAN bus communication quality using a scope or advanced scan tool
-
Check for aftermarket electronics tapped into the CAN bus
-
Inspect CAN bus wiring for damaged shielding or proximity to high-current wires
-
Test TCM communication reliability over an extended drive cycle
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Which Vehicles Commonly Get P0864?
- 2007-2017 Dodge Charger
- 2008-2018 Chrysler Town and Country
- 2010-2020 Jeep Cherokee
- 2009-2019 Ram 1500
Explore More
Was this helpful?
Send this to whoever is fixing the car — your mechanic, or the person asking what the light means.