Subaru P1718

Subaru P1718 trouble code

Diagnose and fix Subaru P1718 trouble code

A Subaru P1718 trouble code is defined as AT Can communication circuit. The CAN bus is the digital communications circuit in the vehicle and when it’s down, you most likely can’t communicate with the modules using a scan tool.

This is a relatively common problem on Subarus and can sometimes be fixed using the P1718 reset procedure shown below. However, if you try that and it still has the code or won’t start, your problem is most likely in the inhibitor switch (most people call it the neutral/safety switch) located on the right side of the transaxle.

Subaru P1718 reset procedure

This is sometimes caused by a logic lock in the computer. It’s just like your laptop freezing up and you having to do a reboot. So here’s the Subaru “reboot” procedure.

1. Disconnect the negative battery terminal and let the vehicle sit for at least an hour (if not overnight).
2. Touch the disconnected negative battery terminal to the positive battery terminal/cable. You want to create a short to drain the computer’s capacitors. Don’t worry, you’ve disconnected the negative cable from the battery so you won’t short the battery.Have the keyless remote ready as you do this
3. Disconnect the negative cable from the positive. Then touch the negative to the positive again
4. Reconnect the negative cable to the negative battery post and immediately cycle the keyless remote to lock and unlock the doors.
5. Get in the vehicle and turn the key to the RUN position. The dash gauges will sweep up and then down. Turn the key to OFF. Repeat this FOUR times.
6. Try starting the vehicle. If it starts, you successfully rebooted the CAN bus. If not, you’ll have to do the full Subaru P1718 diagnostic procedure.

© 2020 Rick Muscoplat