Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car's computer is having trouble talking to the part that controls how the car changes gears.
The code P1599 indicates a communication issue between the vehicle's main computer and the transmission control module via the CAN bus.
The Controller Area Network (CAN) bus is a robust vehicle bus standard that allows microcontrollers and devices to communicate with each other without a host computer. The Transmission Control Module (TCM) relies on the CAN bus to receive and send messages to other modules. A timeout message indicates that the expected communication did not occur within a specified time frame, suggesting a possible disruption or fault in the communication network.
• Check Engine Light is on
• Transmission may not shift properly
• Vehicle may enter limp mode
• Faulty Transmission Control Module (TCM)
• Damaged or corroded CAN bus wiring
• Faulty connectors or poor electrical connections
CAN: Controller Area Network, a vehicle bus standard for communication.
TCM: Transmission Control Module, a device that controls the transmission.
• Check for other related trouble codes
• Inspect the CAN bus wiring and connectors for damage or corrosion
• Test the functionality of the Transmission Control Module
• Repair or replace damaged wiring or connectors
• Replace the Transmission Control Module if faulty
• Clear the codes and test drive the vehicle to confirm the repair
• OBD-II scanner
• Multimeter
• Wiring diagram for the vehicle
$150 - $800
Moderate
• Chevrolet Malibu
• Pontiac Grand Am
• Saturn L-Series
• Regularly inspect and maintain wiring harnesses
• Ensure all connectors are secure and free of corrosion
• Perform routine diagnostic checks
Communication Error
• Do not ignore the Check Engine Light; have the vehicle inspected promptly.
• Avoid driving the vehicle if it is in limp mode to prevent further damage.
Check with the vehicle manufacturer for any applicable recalls or extended warranties related to the transmission control module.
This code has been observed in vehicles with aging electrical systems or those exposed to harsh environmental conditions.
Moderate – Address the issue soon to avoid potential transmission problems.
Driving with a malfunctioning transmission control module can lead to unsafe driving conditions.
• Vehicle must be running
• Diagnostic tool connected to the OBD-II port
The Transmission Control Module is usually located near the transmission or inside the engine compartment.
Q: Can I drive with a P1599 code?
A: It is not recommended to drive with this code active as it may lead to transmission issues.
Q: How do I clear a P1599 code?
A: Use an OBD-II scanner to clear the code, but ensure the underlying issue is fixed first.
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