Notes On Trouble Codes

When certain trouble codes occur, MIL on instrument panel will not come on. For designation of MIL operation on certain trouble codes, see appropriate TROUBLE CODE IDENTIFICATION table under TROUBLE CODE IDENTIFICATION.
When certain malfunctions or trouble codes initially occur, they will be temporarily stored in ECM memory, but MIL on instrument panel will not come on.

The second time malfunction or trouble code is detected, MIL on instrument panel will then come on, provided ignition is turned off and then back on after malfunction or trouble code was first detected. This is referred to as the Two Trip Detection Logic and only applies to specified trouble codes. See TWO TRIP DETECTION LOGIC TROUBLE CODES table.

TWO TRIP DETECTION LOGIC TROUBLE CODES ⁽²⁾

Application

⁽¹⁾ Trouble Code

Tercel

21, 25, 26 & 71

⁽¹⁾	Trouble codes may not apply to all models, as some trouble codes are used only on Calif. models.

⁽²⁾	Two Trip Detection Logic is used on Trouble Code 21 on all except Calif. models.

In Normal Mode, MIL on instrument panel will go off after malfunction is repaired, but trouble codes, except ECM non-memory trouble codes, will be retained in ECM memory until cleared. ECM non-memory trouble codes are not stored in ECM memory. See ECM NON-MEMORY TROUBLE CODES table.

ECM NON-MEMORY TROUBLE CODES

Application	Trouble Code
Normal Mode	51