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 a part that helps control the gear shifting.
The P085A code indicates a communication issue between the vehicle's main computer (ECU) and the Gear Shift Control Module B.
The Gear Shift Control Module B is responsible for managing the electronic signals that control the gear shifting process. When the ECU detects a fault in the communication circuit with this module, it triggers the P085A code.
• Check Engine Light is on
• Transmission may not shift properly
• Vehicle may enter limp mode
• Faulty Gear Shift Control Module B
• Damaged or corroded wiring/connectors
• Faulty ECU
ECU: Engine Control Unit
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code
• Inspect wiring and connectors for damage or corrosion
• Test the Gear Shift Control Module B for functionality
• Repair or replace damaged wiring/connectors
• Replace the Gear Shift Control Module B
• Reprogram or replace the ECU if necessary
• OBD-II scanner
• Multimeter
• Screwdrivers and wrenches
$200 - $800
Moderate
• Ford F-150
• Chevrolet Silverado
• Honda Accord
• Regular maintenance checks
• Keep wiring and connectors clean and dry
• Avoid harsh driving conditions
Communication Issue
• Avoid driving long distances until repaired
• Consult a professional mechanic
• Do not ignore the Check Engine Light
Check with the vehicle manufacturer for warranty coverage on electronic components.
This code has been reported in vehicles with electronic gear shift systems, particularly in models with higher mileage.
Moderate – It should be addressed soon to avoid transmission issues.
Driving with a malfunctioning transmission can be unsafe and may lead to further damage.
• Vehicle must be in a safe location
• Ensure the vehicle is turned off before inspecting wiring
The Gear Shift Control Module B is typically located near the transmission or within the center console.
Q: Can I drive with the P085A code?
A: It's not recommended as it may lead to transmission issues.
Q: How can I clear the P085A code?
A: The code can be cleared with an OBD-II scanner after repairs are made.
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