ABS + Traction Control Lights On
 

Before I go ordering a set of wheel speed sensors can anyone tell me if I'm missing a step to diagnose my problem?

Problem: ABS + traction control lights come on and stay on. Started after an autocross day on my drive home.

Fix Attempts:
1. Checked brake fluid level, lights came back.
2. Filled brake fluid level flush with full line, lights came back.
3. Inspected sensor wiring at wheels, nothing obviously wrong.
4. ECU scan, no codes.
5. Inspected rear sensors, looks fine.

I had that happen once and it turned out that the sensor bolt on the differential came loose.

I just checked the rear wires and everything is connected and looks good. Any other ideas?

You need to scan the ABS module for codes and start there.

The cheapest option I know of is the app OBDFusion ($7-14) with the $14 Nissan enhanced diagnostic add on and a $10 wireless OBD scanner.

Then you can scan all the modules on your car's network, including the ABS module.
You can also view the individual wheel speeds in real time - very helpful!!

Here is a video that shows it on a G37:

Ah that’s super helpful. My odb scanner/software is old and janky and I didn’t realize it wouldn’t scan the abs module. Amazon to the rescue! I’ll post my results in a few days once the new scanner shows up.

I was able to read the codes on the ABS system and got the following.
C1104 - Left front sensor
C1107- Right front sensor 2
C1108 - Left front sensor 2
C1155 - Brake Fluid level low
C1109 - Power and system ground fault

This seems more than a simple sensor issue. Could the ABS module be going bad on me?

I had intermittent problems like this where I also lost instruments functions. It turned out to be defective ABS controller which I believe was causing fault on CAN bus. Fortunately, it was replaced under warranty; but it took almost 2 months for my dealer to get a replacement part from Japan and this was after escalating the issue as high as possible, because I said (and my dealer agreed) this was a safety issue.

Hope your outcome is different; but I doubt you will able to diagnose by yourself and just want to warn you not to go replacing a bunch of parts before you get complete diagnosis.

Check you taillights, happened to me before and it was my taillight and brake light fuse that had blown. My trailer wire adapter had shorted out blowing the fuses.

Yeah I’m taking it in to my mechanic. I do think my abs module is faulty or there is a wiring issue somewhere though. Doesn’t make sense that 3 sensors would simultaneously go bad on me.

Ok last update here... I forgot to clear the ABS codes to see which would come back. Ended up being a left wheel speed sensor. I've driven about 300 miles now after swapping the sensor and no codes have come back.