" Fail Safe " .)
TWO TRIP DETECTION LOGIC
When a malfunction is detected for the first time, 1st tr ip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL lights up. The MIL lights up at the same time when the DTC is stored. <2nd
trip> The “trip” in the “Two Trip Detection Logic” m eans a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic item s will cause the ECM to light up or blink the MIL,
and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
DTC AND FREEZE FRAME DATA
DTC and 1st Trip DTC Emission-related diagnostic information Diagnostic service
Diagnostic Trouble Code (DTC) Service $03 of SAE J1979
Freeze Frame data Service $02 of SAE J1979
System Readiness Test (SRT) code Service $01 of SAE J1979
1st Trip Diagnostic Trouble Code (1st Trip DTC) Service $07 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limits Service $06 of SAE J1979
Calibration ID Service $09 of SAE J1979 DTC 1st trip DTC
Freeze
Frame data 1st trip Freeze
Frame data SRT code SRT status Test value
CONSULT-III × × × × × × —
GST × × × —× × ×
ECM × ×* — — — ×— Items
MIL DTC 1st trip DTC
1st trip 2nd trip 1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
displaying
Blinking Lighting
up Blinking
Lighting
up
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected ×
— — — — — ×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected — —
×— — ×— —
One trip detection diagnoses
(Refer to EC-475, " DTC Index " .)
—
×— — ×— — —
Except above — — — ×— × × —
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The 1st trip DTC (whose number is the same as the DT
C number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously , and the 1st trip DTC did not recur, the 1st trip DTC
will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunc tion is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in t he ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL light s up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. Fo r malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC fr om the ECM memory are described in “How to Erase
DTC and 1st Trip DTC”.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-475, " DTC Index " . These items are
required by legal regulations to c ontinuously monitor the system/component . In addition, the items monitored
non-continuously are also displayed on CONSULT-III.
1st trip DTC is specified in Service $07 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL
and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-22, " Work Flow " . Then perform DTC CONFIR-
MATION PROCEDURE or Component Function Check to tr y to duplicate the malfunction. If the malfunction is
duplicated, the item requires repair.
Freeze Frame Data and 1st Trip Freeze Frame Data The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short-term fuel trim, long-term fuel trim, engi ne speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are ca lled freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame data can only be di splayed on the CONSULT-III screen, not on the GST.
Only one set of freeze frame data (either 1st trip freez e frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM me mory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (P riority: 2) was detected and the freeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st tr ip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If fr eeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame dat a (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM memory are described in “How to Erase DTC and 1st Trip
DTC”.
How to Read DTC and 1st Trip DTC DTC and 1st trip DTC can be read by the following methods.
With CONSULT-III
CONSULT-III displays the DTC in “SELF DIAGNOSTIC RESULT” mode.
Examples: P0340, P0850, P1148, etc. Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0304
Fuel Injection System Function — DTC: P0171, P0172
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
DTC Index " ), skip step 1.
1. Erase DTC in TCM. Refer to AT-39, " OBD-II Diagnostic Trouble Code (DTC) " .
2. Select “ENGINE” with CONSULT-III.
3. Select “SELF DIAGNOSTIC RESULT”.
4. Touch “ERASE”. (DTC in ECM will be erased.)
With GST
NOTE:
If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least
10 seconds and then turn it ON (engine stopped) again.
1. Select Service $04 with GST (Generic Scan Tool).
No Tools
NOTE:
If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least
10 seconds and then turn it ON (engine stopped) again.
1. Erase DTC in ECM. Refer to HOW TO ERASE DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC
RESULTS).
• If the battery is disconnected, the emission-related diagnostic information will be cleared within 24
hours.
• The following data are cleared when the ECM memory is erased.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
Actual work procedures are explained using a DTC as an ex ample. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979.
As part of an enhanced emissions test for Inspection & Ma intenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspec tion due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
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If a vehicle has failed the state emissions inspection
due to one or more SRT items indicating “INCMP”, review
the flowchart diagnostic sequence on the next figure.
How to Display SRT Status WITH CONSULT-III
Selecting “SRT STATUS” in “DTC CONFIRMATION” mode with CONSULT-III.
For items whose SRT codes are set, a “CMPLT” is di splayed on the CONSULT-III screen; for items whose
SRT codes are not set, “INCMP” is displayed.
NOTE:
Though displayed on the CONSULT-III scr een, “HO2S HTR” is not SRT item.
WITH GST
Selecting Service $01 with GST (Generic Scan Tool)
NO TOOLS
A SRT code itself can not be displayed while only SRT status can be.
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown below. • When all SRT codes are set, MIL lights up continuously.
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*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze fr ame data. The items appear on CONSULT-III screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-90, " Diagnosis Description " .
*3: Always “CMPLT ” is displayed.
WORK SUPPORT MODE
Work Item
*: This function is not necessary in the usual service procedure.
SELF DIAGNOSTIC RESULT MODE
Self Diagnostic Item Regarding items of DTC and 1st trip DTC, refer to EC-475, " DTC Index " .)
Freeze Frame Data and 1st Trip Freeze Frame Data WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE • FUEL PUMP WILL STOP BY TOUCHING “START” DUR- ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS. When releasing fuel pressure from
fuel line
IDLE AIR VOL LEARN • THE IDLE AIR VOLUME THAT KEEPS THE ENGINE WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM. When learning the idle air volume
SELF-LEARNING CONT • THE COEFFICI ENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing mixture ratio self-
learning value
EVAP SYSTEM CLOSE CLOSE THE EVAP CANISTER VENT CONTROL VALVE IN ORDER TO MAKE EVAP SYSTEM CLOSE UNDER THE
FOLLOWING CONDITIONS.
• IGN SW ON
• ENGINE NOT RUNNING
• AMBIENT TEMPERATURE IS ABOVE 0 °C (32 °F).
• NO VACUUM AND NO HIGH PRESSURE IN EVAP SYS- TEM
• FUEL TANK TEMP. IS MORE THAN 0 °C (32 °F).
• WITHIN 10 MINUTES AFTER STARTING “EVAP SYS- TEM CLOSE”
• WHEN TRYING TO EXECUTE “EVAP SYSTEM CLOSE”
UNDER THE CONDITION EXCEPT ABOVE, CONSULT-
II WILL DISCONTINUE IT AND DISPLAY APPROPRIATE
INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-III MAY DIS-
PLAY “BATTERY VOLTAGE IS LOW. CHARGE BAT-
TERY”, EVEN IN USING CHARGED BATTERY. When detecting EVAP vapor leak
point of EVAP system
VIN REGISTRATION • IN THIS MODE, VIN IS REGIST ERED IN ECM. When registering VIN in ECM
TARGET IDLE RPM ADJ* • IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ* • IDLE CONDITION When adjusting target ignition timingFreeze frame data
item* Description
DIAG TROUBLE
CODE
[PXXXX] • The engine control co
mponent part/control system has a trouble code, it is displayed as PXXXX. (Refer to
EC-475, " DTC Index " .)
FUEL SYS-B1 • “Fuel injection system status” at the moment a malfunction is detected is displayed.
• One mode in the following is displayed. Mode2: Open loop due to detected system malfunction
Mode3: Open loop due to driving conditions (power enrichment, deceleration enleanment)
Mode4: Closed loop - using oxygen sensor(s) as feedback for fuel control
Mode5: Open loop - has not yet satisfied condition to go to closed loop
P0455
EC-329 EVP V/S LEAK P0456/P1456* P0456
EC-335A/F SEN1
A/F SEN1 (B1) P1278/P1279 P0133
EC-198A/F SEN1 (B1) P1276 P0130
EC-182HO2S2
HO2S2 (B1) P1146 P0138
EC-212HO2S2 (B1) P1147 P0137
EC-204HO2S2 (B1) P139 P0139
EC-221 DTC Index " .
Service $03 DTCs This diagnostic service gains access to emission-related power train trouble codes which
were stored by ECM.
Service $04 CLEAR DIAG INFO This diagnostic service can clear all emission-related diagnostic information. This in-
cludes:
• Clear number of diagnostic trouble codes (Service $01)
• Clear diagnostic trouble codes (Service $03)
• Clear trouble code for freeze frame data (Service $01)
• Clear freeze frame data (Service $02)
• Reset status of system monitoring test (Service $01)
• Clear on board monitoring test results (Service $06 and $07)
Service $06 (ON BOARD TESTS) This diagnostic service accesses the results of on board diagnostic monitoring tests of
specific components/systems that are not continuously monitored.
Service $07 (ON BOARD TESTS) This diagnostic service enables the off board test drive to obtain test results for emission-
related powertrain components/systems that are continuously monitored during normal
driving conditions.
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INSPECTION PROCEDURE
1. Turn ignition switch OFF.
2. Connect “GST” to data link connector (1), which is located under LH dash panel.
3. Turn ignition switch ON.
4. Enter the program according to instruction on the screen or in the operation manual.
(*: Regarding GST screens in this section, sample screens are
shown.)
5. Perform each diagnostic mode according to each service proce- dure.
For further information, see th e GST Operation Manual of
the tool maker.
Service $08 —
This diagnostic service can close EVAP system in ignition switch ON position (Engine
stopped). When this diagnostic service is performed, EVAP canister vent control valve can
be closed.
In the following conditions, this diagnostic service cannot function.
• Low ambient temperature
• Low battery voltage
• Engine running
• Ignition switch OFF
• Low fuel temperature
• Too much pressure is applied to EVAP system
Service $09 (CALIBRATION ID) This diagnostic service enables the off-board test device to request specific vehicle infor-
mation such as Vehicle Identification Number (VIN) and Calibration IDs.
Diagnostic Service Function
SEF416S
YES >> Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to
EC-148, " DTC
Logic " . Then GO TO 29.
NO >> GO TO 23. YES >> GO TO 24.
NO >> More than the SP value: Replace mass air flow sensor, and then GO TO 29. ADDITIONAL SERVICE WHEN REPLACING CO
NTROL UNIT : Special Repair Require-ment " .
>> GO TO 29. YES >> GO TO 27.
NO >> Repair or replace malfunctioning part, and then GO TO 26. YES >> INSPECTION END
NO >> Less than the SP value: GO TO 27. YES >> GO TO 28.
NO >> Less than the SP value: Replace mass air flow sensor, and then GO TO 30.