Otherwise, code(s) would remain in the ECUs memory indefinitely and would appear along with a new code in the event of a future problem. Check your emissions decal under the hood to confirm if you have an OBD2 compliant vehicle.Īll trouble codes must be purged from the ECUs memory after repairing the faults. For example, for code 53, the light will flash five times followed by a short pause and three more flashes.ĩ6 & later are OBD2 systems and require a scantool Note: We are finding that some 94 & 95 Toyota vehicles are OBD2 compliant and require a scan tool. The light will flash in a pattern to indicate the two digit trouble code. Watch and count the number of times the check engine light flashes. Turn the key in the ignition to start the engine. Jumper wires are found at electronic stores and online.
The owner's manual for your Toyota will have a diagram.Īttach the TE1 terminal to the E1 terminal with a jumper wire. It is usually found under the passenger side dashboard or in the fender. Locate the diagnostic connector in the engine compartment of your Toyota. To extract DTCs from the computer for diagnostic purposes, the Self Test connector is used.
The display will indicate any diagnostic codes stored in the ECU's keep alive memory.Trouble Codes › Toyota trouble Codes › Toyota OBD trouble Codes When the "DIAG" message appears on the display, pressing and holding the "Set" key for three seconds will put the TCCS system into diagnostic mode. This display can be used to read diagnostic codes by simply pressing and holding the monitor "Select" and "Input M" keys together, for three seconds, with the ignition switch in the "on" position. Super Monitor Display: On some 1983 through 1987 Cressida and Supra models, a Super Monitor trip computer was offered as optional equipment. It is important to refer to the proper repair manual for specific information about diagnostic connector location, code format, and proper procedures for the vehicle you are troubleshooting. An analog voltmeter must be used to read the codes from the VF terminal of the EFI Service Connector.ĭepending on the vintage of the system being tested, the codes will be displayed in either one or two digit format. On '83 through '85 Cressida and Supra models, the check engine light does not flash diagnostic codes. Low voltage on T causes the ECU to enter diagnostic mode, producing diagnostic codes on the check engine light. When the T terminal is grounded with the ignition switch in the "on" position, the ECU sees the voltage at terminal T go low. Jumper check connector terminals T (TE1) to E1.Confirm that the throttle is closed (IDL contact on).Turn the ignition switch to the "on" position and make sure that the check engine light is on.Locate the check connector under the hood and identify the T (TE1 on late model TCCS) and E1 terminals.The E1 ground circuit is also located in the check connector. When grounded, this terminal triggers the self diagnostic feature of the ECU. All engines equipped with self diagnostic systems have one terminal of the check connector identified as T or TE1. The procedure to examine the ECU memory for diagnostic codes is typically very simple regardless of which vintage engine being diagnosed.
Earlier models use this same multiple terminal or a two-terminal check connector, all located under the hood. All late model TCCS applications, from 1988, use a multiple terminal diagnostic check connector. There are several different types and locations of diagnostic connectors which are used to trigger and, in some cases, read diagnostic code output from Toyota EFI engines.