Service Repair

Toyota Says it Might be the Bulbs

Oct. 16, 2020

Some 2014-2020 Toyota 4Runner vehicles may experience the ABS light on, with DTC C0226, C0236, C0246 and C0256 stored in the ABS system.

Mike Mavrigian

Information courtesy of Mitchell 1

Some 2014-2020 Toyota 4Runner vehicles may experience the ABS light on, with DTC C0226, C0236, C0246 and C0256 stored in the ABS system.

Inspect the ABS connector for signs of damage. If OK, go to Step 2.
Use a Picoscope to monitor the ground to the Skid Control ECU with the engine running and headlights on, then with the headlights off. If the ground circuit voltage fluctuates with the headlights on as compared to headlights off, go to Step 3.
Inspect the headlight bulbs for any aftermarket parts such as LED or HID bulbs. If aftermarket bulbs are found, perform the same tests with factory headlight bulbs.

Example of skid control ground with headlights on. Note the difference with headlights off.

Example of skid control ground with headlights off.

About the Author

Mike Mavrigian | Motor Age Editor

Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.

About the Author

Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.