Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble talking to the part that controls the transmission. It's like when two people can't hear each other on a phone call.
The Transmission Control Module (TCM) is not communicating properly with the car's main computer, which can affect how the car shifts gears.
The P0864 code indicates a problem with the communication circuit between the Transmission Control Module (TCM) and the Powertrain Control Module (PCM). This may be due to a wiring issue, a fault in the TCM, or an issue with the PCM itself.
• Check Engine Light is on
• Transmission may not shift properly
• Poor fuel economy
• Vehicle may go into limp mode
• Erratic shifting
• Faulty TCM
• Wiring issues in the communication circuit
• Faulty PCM
• Poor electrical connections
• Software issues
TCM: Transmission Control Module
PCM: Powertrain Control Module
• Check for other related codes
• Inspect wiring and connectors for damage
• Test the TCM and PCM for faults
• Check for software updates
• Perform a continuity test on the communication circuit
• Repair or replace damaged wiring
• Replace faulty TCM
• Update or reprogram the PCM
• Ensure all connections are secure
• Replace faulty PCM if necessary
• OBD-II scanner
• Multimeter
• Wiring diagram
• Screwdrivers
• Socket set
$150 - $1200
Moderate
• Dodge Ram
• Jeep Grand Cherokee
• Chrysler 300
• Regularly inspect wiring and connections
• Keep software up to date
• Avoid harsh driving conditions
Communication Issue
• Have the vehicle inspected by a professional
• Avoid driving long distances until repaired
Check if the vehicle's powertrain warranty covers TCM issues.
This code has been reported in vehicles with known transmission communication issues, often related to wiring or module faults.
Moderate – Should be addressed soon to avoid transmission damage.
Driving with this code may lead to unsafe driving conditions due to erratic transmission behavior.
• Vehicle at operating temperature
• Engine running
The TCM is usually located near the transmission or integrated within the PCM.
Q: Can I drive with a P0864 code?
A: It's not recommended to drive for long distances as it may cause further transmission issues.
Q: What happens if I ignore the P0864 code?
A: Ignoring the code can lead to transmission problems and potentially higher repair costs.
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