After my Engine Management light came on I did hours of browsing and research and found thisI thought it may be of use for some 1 else as I couldn't find this on UKSO siteHope it helps ECU Diagnostic Codes for many Toyota ECUs Some codes may not exist in earlier or non-applicable engine ECU’s but all codes are common among many Toyota ECUs. It is essential that you do have the proper manuals and skills necessary to perform diagnostic and repairs. This list is to assist those who are qualifie