Page 2617 of 4770

DI07A±06
FI0534
A06134
TOYOTA Hand±Held Tester
± DIAGNOSTICSENGINE (1MZ±FE)
DI±197
432 Author: Date:
PRE±CHECK
1. DIAGNOSIS SYSTEM
(a) Description
When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect to the vehicle the OBD II scan
tool complying with SAE J1978 or TOYOTA hand±
held tester, and read off various data output from
the vehicle's ECM.
OBD II regulations require that the vehicle's on±
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the emission control
system/components or in the powertrain control
components which affect vehicle emissions, or a
malfunction in the computer. In addition to the MIL
lighting up when a malfunction is detected, the ap-
plicable Diagnostic Trouble Codes (DTC) pre-
scribed by SAE J2012 are recorded in the ECM
memory (See page DI±211).
If the malfunction does not reoccur in 3 consecutive trips, the
MIL goes off but the DTCs remain recorded in the ECM memory.
To check the DTC, connect the OBD II scan tool or
TOYOTA hand±held tester to Data Link Connector
3 (DLC3) on the vehicle. The OBD II scan tool or
TOYOTA hand±held tester also enables you to
erase the DTC and check freezed frame data and
various forms of engine data (For operating instruc-
tions, see the OBD II scan tool's instruction book.).
DTC include SAE controlled codes and manufac-
turer controlled codes. SAE controlled codes must
be set as prescribed by the SAE, while manufactur-
er controlled codes can be set freely by the
manufacturer within the prescribed limits (See DTC
chart on page DI±211).
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DI±198
± DIAGNOSTICSENGINE (1MZ±FE)
433 Author: Date:
The diagnosis system operates in normal mode
during normal vehicle use. It also has a check mode
for technicians to simulate malfunction symptoms
and troubleshoot. Most DTC use 2 trip detection
logic* to prevent erroneous detection, and ensure
thorough malfunction detection. By switching the
ECM to check mode when troubleshooting, the
technician can cause the MIL to light up for a mal-
function that is only detected once or momentarily
(TOYOTA hand±held tester only). (See page
DI±197)
*2 trip detection logic:
When a malfunction is first detected, the malfunc-
tion is temporarily stored in the ECM memory. (1st
trip)
If the same malfunction is detected again during the second
drive test, this second detection causes the MIL to light up. (2nd
trip) (However, the IG switch must be turned OFF between the
1st trip and the 2nd trip.).
Freeze frame data:
Freeze frame data records the engine condition
when a misfire (DTCs P0300 ~ P0306) or fuel trim
malfunction (DTCs P0171, P0172) or other mal-
function (first malfunction only), is detected.
Because freeze frame data records the engine
conditions (fuel system, calculated load, engine
coolant temperature, fuel trim, engine speed, ve-
hicle speed, etc.) when the malfunction is detected,
when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the en-
gine warmed up or not, the air±fuel ratio lean or rich,
etc. at the time of the malfunction.
Priorities for troubleshooting:
If troubleshooting priorities for multiple DTC are given in the ap-
plicable DTC chart, these should be followed.
If no instructions are given troubleshoot DTC according to the
following priorities.
(1) DTC other than fuel trim malfunction (DTCs P0171,
P0172), EGR (DTCs P0401, P0402) and misfire
(DTCs P0300 ~ P0306).
(2) Fuel trim malfunction (DTCs P0171, P0172) and
EGR (DTCs P0401, P0402).
(3) Misfire (DTCs P0300 ~ P0306).
Page 2619 of 4770

N09214
DLC3
S04159
± DIAGNOSTICSENGINE (1MZ±FE)
DI±199
434 Author: Date:
(b) Check the DLC3.
The vehicle's ECM uses ISO 9141±2 for communication.
The terminal arrangement of DLC3 complies with SAE
J1962 and matches the ISO 9141±2 format.
Terminal No.Connection / Voltage or ResistanceCondition
7Bus Line / Pulse generationDuring transmission
4Chassis Ground e Body Ground /1 W or lessAlways
5Signal Ground e Body Ground /1 W or lessAlways
16Battery Positive e Body Ground /9 ~ 14 VAlways
HINT:
If your display shows ºUNABLE TO CONNECT TO VEHICLEº
when you have connected the cable of the OBD II scan tool or
TOYOTA hand±held tester to DLC3, turned the ignition switch
ON and operated the scan tool, there is a problem on the ve-
hicle side or tool side.
If communication is normal when the tool is connected to
another vehicle, inspect DLC3 on the original vehicle.
If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tool itself, so consult the Service Department listed in the
tool's instruction manual.
2. INSPECT DIAGNOSIS (Normal Mode)
(a) Check the MIL.
(1) The MIL comes on when the ignition switch is turned
ON and the engine is not running.
HINT:
If the MIL does not light up, troubleshoot the combination meter
(See page BE±46).
(2) When the engine started, the MIL should go off. If
the lamp remains on, the diagnosis system has de-
tected a malfunction or abnormality in the system.
(b) Check the DTC.
NOTICE:
TOYOTA hand±held tester only: When the diagnosis sys-
tem is switched from normal mode to check mode, it erases
all DTC and freezed frame data recorded in normal mode.
So before switching modes, always check the DTC and
freezed frame data, and note them down.
(1) Prepare the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand±held tester.
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DI±200
± DIAGNOSTICSENGINE (1MZ±FE)
435 Author: Date:
(2) Connect the OBD II scan tool or TOYOTA hand±
held tester to DLC3 at the lower center of the instru-
ment panel.
(3) Turn the ignition switch ON and push the OBD II
scan tool or TOYOTA hand±held tester switch ON.
(4) Use the OBD II scan tool or TOYOTA hand±held
tester to check the DTC and freezed frame data and
note them down (For operating instructions, see the
OBD II scan tool's instruction book.).
(5) See page DI±197 to confirm the details of the DTC.
NOTICE:
When simulating symptoms with an OBD II scan tool
(excluding TOYOTA hand±held tester) to check the
DTC, use normal mode. For code on the DTC chart
subject to º2 trip detection logicº, performe the fol-
lowing either action.
Turn the ignition switch OFF after the symptom is
simulated the first time. Then repeat the simulation
process again. When the problem has been simulated
twice, the MIL lights up and the DTCs are recorded in
the ECM.
Check the 1st trip DTC using Mode 7 (Continuous Test
Results) for SAE J1979.
(c) Clear the DTC.
The DTCs and freezed frame data will be erased by either
action.
Operating the OBD II scan tool (complying
with SAE J1978) or TOYOTA hand±held tes-
ter to erase the codes. (See the OBD II scan
tool's instruction book for operating instruc-
tions.)
Disconnecting the battery terminals or EFI
fuse.
NOTICE:
If the TOYOTA hand±held tester switches the ECM from
normal mode to check mode or vice±versa, or if the ignition
switch is turned from ON to ACC or OFF during check
mode, the DTCs and freezed frame data will be erased.
3. INSPECT DIAGNOSIS (Check Mode)
HINT:
TOYOTA hand±held tester only:
Compared to the normal mode, the check mode has an in-
creased sensitivity to detect malfunctions.
Furthermore, the same diagnostic items which are detected in
the normal mode can also be detected in the check mode.
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FI3605
Flashing
ON
OFF
0.13 Seconds
± DIAGNOSTICSENGINE (1MZ±FE)
DI±201
436 Author: Date:
(a) Check the DTC.
(1) Initial conditions.
Battery positive voltage 11 V or more
Throttle valve fully closed
Transmission in ºPº or ºNº position
Air conditioning switched OFF
(2) Turn ignition switch OFF.
(3) Prepare the TOYOTA hand±held tester.
(4) Connect the TOYOTA hand±held tester to the
DLC3 at the lower center of the instrument panel.
(5) Turn the ignition switch ON and push the TOYOTA
hand±held tester switch ON.
(6) Switch the TOYOTA hand±held tester normal mode
to check mode (Check that the MIL flashes.).
NOTICE:
If the TOYOTA hand±held tester switches the ECM from
normal mode to check mode or vice±versa, or if the igni-
tion switch is turned from ON to ACC or OFF during check
mode, the DTC and freezed frame data will be erased.
(7) Start the engine (The MIL goes out after the engine
start.).
(8) Simulate the conditions of the malfunction de-
scribed by the customer.
NOTICE:
Leave the ignition switch ON until you have checked the
DTC, etc.
(9) After simulating the malfunction conditions, use the
TOYOTA hand±held tester diagnosis selector to
check the DTC and freezed frame data, etc.
HINT:
Take care not to turn the ignition switch OFF. Turning the ignition
switch OFF switches the diagnosis system from check mode to
normal mode. So all DTC, etc. are erased.
(10) After checking the DTC, inspect the applicable cir-
cuit.
Page 2622 of 4770

DI±202
± DIAGNOSTICSENGINE (1MZ±FE)
437 Author: Date:
4. FAIL±SAFE CHART
If any of the following codes is recorded, the ECM enters fail±safe mode.
DTC No.Fail±Safe OperationFail±Safe Deactivation Conditions
P0100Ignition timing fixed at 10° BTDCReturned to normal condition
P0110Intake air temperature is fixed at 20°C (68°F)Returned to normal condition
P0115Engine coolant temperature is fixed at 80°C (176°F)Returned to normal condition
P0120VTA is fixed at 0°
The following condition must be repeated at least 2 times
consecutively
(a) Vehicle speed: 0km/h (0mph)
(b) VTA 0.1 V and 0.95 V
P0135
P0141
P0155The heater circuit in which an abnormality is detected is
turned offIgnition switch OFF
P0325
P0330Max. timing retardationIgnition switch OFF
P1300Fuel cutIGF signal is detected for 6 consecutive ignition
5. CHECK FOR INTERMITTENT PROBLEMS
TOYOTA HAND±HELD TESTER only:
By putting the vehicle's ECM in check mode, 1 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 page DI±197).
(2) Set the check mode (See page DI±197).
(3) Perform a simulation test (See page IN±21).
(4) Check the connector and terminal (See page IN±31).
(5) Handle the connector (See page IN±31).
6. BASIC INSPECTION
When the malfunction code is not confirmed in the DTC check, troubleshooting should be performed in the
order for all possible circuits to be considered as the causes of the problems. In many cases, by carrying
out the basic engine check shown in the following flow chart, the location causing the problem can be found
quickly and efficiently. Therefore, use of this check is essential in engine troubleshooting.
1 Is battery positive voltage 11 V or more when engine is stopped ?
NO Charge or replace battery.
YES
Page 2623 of 4770
P00495
Outside
Inside
± DIAGNOSTICSENGINE (1MZ±FE)
DI±203
438 Author: Date:
2 Is engine cranked?
NO Proceed to page ST±18 and continue to trouble-
shoot.
YES
3 Does engine start?
NO Go to step 7.
YES
4 Check air filter.
PREPARATION:
Remove the air filter.
CHECK:
Visually check that the air filter is not dirty or excessive oily.
HINT:
If necessary, clean the filter with compressed air. First blow from
inside thoroughly, then blow from outside of the filter.
NG Repair or replace.
OK
Page 2624 of 4770

A00209
DLC1
TE1
E1
SST
DLC1
P12915
P12952
DI±204
± DIAGNOSTICSENGINE (1MZ±FE)
439 Author: Date:
5 Check idle speed.
PREPARATION:
(a) Warm up the engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off air conditioning.
(d) Shift transmission into ºNº position.
(e) Connect the OBD II scan tool or TOYOTA hand±held tester to DLC3 on the vehicle.
CHECK:
Use CURRENT DATA to check the idle speed.
OK:
Idle speed: 650 ~ 750 rpm
NG Proceed to problem symptoms table on
page DI±221.
OK
6 Check ignition timing.
PREPARATION:
(a) Warm up the engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off air conditioning.
(d) Shift transmission into ºNº position.
(e) Keep the engine speed at idle.
(f) Using SST, connect terminals TE1 and E1 of the DLC1.
SST 09843±18020
(g) Using a timing light, connect the tester to check wire.
CHECK:
Check ignition timing.
OK:
Ignition timing: 10° BTDC at idle
NG Proceed to page IG±1 and continue to
troubleshoot.
OK
Proceed to problem symptoms table on page
DI±221.