Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Controller Area Network System: Description
The CAN is a high-speed serial interface for sharing dynamic signals between control modules. CAN communications are SELF CHECKED for errors, if an error is detected the message is ignored by the receiving control module. Due to the high rate of information exchange (500K baud) the system has a high degree of latency. This allows for a high amount of errors to be present without reducing the data transfer rate.
The CAN communication system is a differential bus using a twisted pair, which is normally very reliable. If either or both of the wires of the twisted pair CAN bus is open or short-circuited a CAN time out fault will occur and the automatic TCM defaults to third gear. In order to alert the driver the SPORT and MANUAL warning lights in the instrument pack will flash alternatively.
An error is detected if the ECM receives no CAN messages for at least 0.8 seconds or the duration of the automatic TCM retard request is greater than 10 seconds. See Fig 1 .
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.