Engine Control System Self Diagnostics: Other Toyota Avalon XX20 рестайлинг

TWO-TRIP DETECTION LOGIC

The diagnosis system operates in normal mode during normal vehicle use. It also has a check mode for technicians to simulate malfunction symptoms and trouble shoot. The 2 trip detection logic is when a malfunction is first detected, the malfunction is temporarily stored in the ECM memory (1st trip). Most DTCs use 2 trip detection logic, to prevent erroneous detection, and ensure thorough malfunction detection. By switching the ECM to check mode when trouble shooting, the technician can cause the MIL to light up for a malfunction that is only detected once or momentarily (hand-held tester only). If the same malfunction is detected again during the second drive test, this second detection causes the MIL to light up (2nd trip). The 2 trip repeats the same mode a second time. However, the ignition switch must be turned OFF between the 1st and 2nd trip.

FREEZE FRAME DATA

Freeze frame data records the engine conditions (fuel system, calculated load, engine coolant temperature, fuel trim, engine speed, vehicle speed, etc.) when a misfire (DTCs P0300-P0306) or fuel trim malfunction (DTCs P0171, P0172, P0174 and P0175) or other malfunction (first malfunction only), is detected. When trouble shooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

If trouble shooting priorities for multiple DTCs are given in the applicable DTC chart, these should be followed. If no instructions are given, trouble shoot DTCs according to the following priorities

1. DTC other than fuel trim malfunction (DTCs P0171, P0172, P0174 and P0175) and misfire (DTCs P0300-P0306).
2. Fuel trim malfunction (DTCs P01071, P0172, P0174 and P0175).
3. Misfire (DTCs P0300-P0306).

FAIL-SAFE CHART

If any of the following codes is recorded, the engine control module (ECM) enters the fail-safe mode. (Scheme 198)

Scheme 198

INTERMITTENT PROBLEMS CHECK (HAND-HELD TESTER ONLY)

By putting the vehicle's ECM in the check mode, one-trip detection logic is possible instead of 2-trip detection logic and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.

1. Clear the DTC. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151954-S22549028572003010900000) .
2. Set the check mode. See «CHECK MODE DTC RETRIEVAL (HAND-HELD TESTER ONLY)»(ref-151954-S36870193002003010900000) under RETRIEVING DIAGNOSTIC TROUBLE CODES.
3. Simulate the conditions of the malfunction described by customer
4. Check the connector and terminal.
5. Handle the connector.

ENGINE OPERATING CONDITION

The values given below for normal condition are representative values, so a vehicle may still be normal even if it's value varies differ from those listed here. So do not decide whether a part is faulty or not solely according to the normal condition here.

1. For CARB Mandated Signals (Scheme 199)
2. For TOYOTA Enhanced Signals (Scheme 200)

Scheme 199

Scheme 200

ENGINE CONTROL MODULE PROGRAMMING

An engine immobilizer system may be used. On models equipped with engine immobilizer system, if engine control module (ECM) is replaced, the ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.

SUMMARY

If no diagnostic trouble codes (DTC) are present and a no start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If no DTCs are present and a driveability condition exists, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).

Confirmation Driving Pattern

For confirmation driving pattern (Scheme 201)

Scheme 201

Note. If you have no hand-held tester, turn the ignition switch OFF after the symptom is simulated the first time. Then repeat the simulation process again.

1. Connect the OBD II scan tool or hand-held tester and record the DTC and the freeze frame data. See «SYSTEM OVERVIEW»(ref-151954-S20682626362003010900000) under SELF-DIAGNOSTIC SYSTEM.
2. Use the hand-held tester to set the check mode. See «TWO-TRIP DETECTION LOGIC»(ref-151954-S01870655182003010900000) under SELF-DIAGNOSTIC SYSTEM.
3. Drive the vehicle several times with the engine speed, load and it's surrounding range shown with the ENGINE SPD, CALC LOAD in the freeze frame data or the MISFIRE RPM, MISFIRE LOAD in the data list. In order to memorize DTC of misfire, it is necessary to drive around MISFIRE RPM, MISFIRE LOAD in the data list for the following period of time. See «DTC P0300-P0306 DATA LIST»(ref-151954-S20528127282003081400000) .
4. Check whether there is misfire or not by monitoring DTC and the freeze frame data. After that, record them.
5. Turn the ignition switch OFF and wait at least 5 seconds.

DTC P0300-P0306 DATA LIST

Confirmation Engine Racing Pattern

For confirmation engine racing pattern (Scheme 202)

Scheme 202