check engine light TOYOTA CAMRY 2000 Service Owner's Manual

DIAGNOSIS SYSTEM
DESCRIPTION
The ECM contains a built±in self±diagnosis system by which
troubles with the engine signal network are detected and a
Malfunction indicator lamp on the instrument panel lights up.
By analyzing various signals as shown in the later table (See
page EG1±300) the Engine Control Module (ECM) detects
system malfunctions relating to the sensors or actuators.
In the normal mode, the self±diagnosis system monitors 14
items, indicated by code No. as shown in EG1±300. A mal-
function indicator lamp informs the driver that a malfunction
has been detected. The light goes off automatically when the
malfunction has been repaired. But the diagnostic trouble
code(s) remains stored in the ECM memory (except for code
Nos. 16). The ECM stores the code(s) until it is cleared by
removing the EFI fuse with the ignition switch off.
The diagnostic trouble code can be read by the number of
blinks of the malfunction indicator lamp when TE1 and E1
terminals on the data link connector 1 or 2 are connected.
When 2 or more codes are indicated, the lowest number
(code) will appear first.
In the test mode, 9 items, indicated by code No. as shown in
EG1±300 are monitored. If a malfunction is detected in any
one of the systems indicated by code Nos. 13, 22, 24, 25, 26,
27, 31, 41 and 71 the ECM lights the malfunction indicator
lamp to warn the technician that malfunction has been de-
tected. In this case, TE2 and E1 terminals on the data link
connector 1 or 2 should be connected as shown later. (See
page EG1±298).
In the test mode, even if the malfunction is corrected, the
malfunction code is stored in the ECM memory even when
the ignition switch is off (except code Nos. 43 and 51). This
also applies in the normal mode. The diagnostic mode (nor-
mal or test) and the output of the malfunction indicator lamp
can be selected by connecting the TE1, TE2 and E1 termi-
nals on the data link connector 1 or 2, as shown later.
A test mode function has been added to the functions of the
self±diagnostic system of the normal mode for the purpose of
detecting malfunctions such as poor contact, which are diffi-
cult to detect in the normal mode. This function fills up the
self±diagnosis system. The test mode can be implemented
by the technician following the appropriate procedures of
check terminal connection and operation described later.
(See page
EG1±298)
± 5S±FE ENGINEDIAGNOSIS SYSTEMEG1±296

Diagnosis Inspection (Normal Mode)
MALFUNCTION INDICATOR LAMP CHECK
1. The Malfunction indicator lamp will come on when the
ignition switch is turned ON and the engine is not run±
ning.
HINT: If the malfunction indicator lamp does not light
up, proceed to troubleshooting of the combination meter
(See page BE±64).
2. When the engine is started, the malfunction indicator
lamp should go off.
If the light remains on, the diagnosis system has detected
a malfunction or abnormality in the system.
DIAGNOSTIC TROUBLE CODE CHECK
1. Turn ignition switch on.
2. Using SST, connect terminals between TE1 and E1 of
data link connector 1 or 2.
SST 09843±18020
As an example, the blinking patterns for codes;normal,
12 and 31 are as shown on the illustration.
4. Check the details of the malfunction using the diagnostic
trouble code table on page EG1±300.
5. After completing the check, disconnect terminals TE1
and E1, and turn off the display.
HINT: I n the event of 2 or more malfunction codes,
indication will begin from the smaller numbered code
and continue in order to the larger.3. Read the diagnostic trouble code from malfunction indi±
cator lamp.
HINT: If a diagnostic trouble code is not output, check
the TE1 terminal circuit (See page EG1±430).
± 5S±FE ENGINEDIAGNOSIS SYSTEMEG1±297

*1; ªONº displayed in the diagnosis mode column indicates that the Malfunction Indicator Lamp is lighted up when a
malfunction is detected. ªOFFº indicates that the ªCHECKº does not light up during malfunction diagnosis, even if a
malfunction is detected. ªN.A.º indicates that the item is not included in malfunction diagnosis.
*2; ªOº in the memory column indicates that a diagnostic trouble code is recorded in the ECM memory when a malfunction
occurs. ªXº indicates that a diagnostic trouble code is not recorded in the ECM memory even if a malfunction occurs.
Accordingly, output of diagnostic results in normal or test mode is performed with the IG switch ON.
*3; Only for California specification vehicles.
*4; Only vehicles with A/T.EGR gas temp. is 70C (158F) or below for 50 sec. under
conditions (a) and (b).
(2 trip detection logic)*
(a) Engine coolant temp.: 80C (176F) or more.
(b) EGR operation possible (Ex. A/T in 3rd speed (5th for
M/T), 55 ± 60 mph (88 ± 96 km/h), Flat road).
(1) 3 sec. or more after engine starts with closed throttle position
switch OFF (IDL).
(2) * Park/Neutral switch OFF (PNP).
(Shift position in ªRº, ªDº, ª2º, or ªLº positions).
(3) A/C switch ON. Open or short in knock sensor circuit with engine speed
between 1,200 rpm and 6,000 rpm.Diagnostic trouble Code
Detecting Condition
Switch Condition
SignalNo starter signal to ECM.
Knock Sensor
Signal
EG R System
Malfunction Number of
MIL Blinks
Starter Signal DTC
No.Circuit
± 5S±FE ENGINEDIAGNOSTIC TROUBLE CODE CHARTEG1±306

CLEAR DIAGNOSTIC TROUBLE CODES
See page EG1±299.
SET TEST MODE
1. With the ignition switch off, using SST, connect the ter±
minals TE2 and E1 of the data link connector 1 and 2.
SST 09843±18020
2. Start the engine and check to see the malfunction indica±
tor lamp to go off.
PERFORM A SIMULATION TEST
Using the symptom simulation (See page IN ±24), apply vibra±
tion to and pull lightly on the wire harness, connector or
terminals in the circuit indicated by the malfunction code.
In this test, if the malfunction indicator lamp light up, it indi±
cates that the place where the wire harness, connector or
terminals being pulled or vibrated has faulty contact. Check
that point for loose connections, dirt on the terminals, poor fit
or other problems and repair as necessary.
HINT: After cancelling out the diagnostic trouble code in
memory and set the test mode, if the malfunction indicator
lamp does not go off after the engine is started, check thor±
oughly for faulty contact, etc., then try the check again. If the
malfunction indicator lamp still does not go off, check and
replace ECM.
CHECK FOR MOMENTARY
INTERRUPTION
As described in the preceding paragraph, abnormality detec±
tion ability in the test mode is increased compared to that in
the normal mode, so that when momentary interruptions or
momentary shorts occur in the ECM signal circuits (G, NE,
THW, THA, PIM, VTA) shown in the table below, the appro±
priate diagnostic trouble code is output.
Accordingly, when the diagnostic trouble codes shown in the
table below (13, 22, 24, 31, 41) are output during the diag±
nostic trouble code check, and inspection of the appropriate
circuits reveals no abnormality, perform the check for momen±
tary interruption as described below.
By performing the check for momentary interruption, the
place where momentary interruptions or momentary shorts are
occurring due to poor contacts can be isolated.
Engine coolant temp. sensor
circuit
Manifold absolute pressure
sensor circuit
Throttle position sensor circuitIntake air temp. sensor circuitG, NE signal circuit (No.2)Circuit DTC
± 5S±FE ENGINECHECK FOR MOMENTARY INTERRUPTIONEG1±309

(1) Shift transmission into ªNº position or neutral.
(2) Warm up engine at normal operating temperature.
(3) Keep the engine speed at idle.
(4) Using SST, connect terminals TE1 and E1 of
data link connector 1.
SST 09843±18020
(5) Using a timing light, connect the tester to
No. 1 high±tension cord.(1) Shift transmission into ªNº position or neutral.
(2) Warm up engine at normal operating temperature.
(3) Switched off all accessories.
(4) Switched off air conditioning.
(5) Connect tachometer test probe to terminal
IG (±) of data link connector 1, and set the
tachometer to the 4±cylinder range.
wNEVER allow tachometer test probe to touch
ground as it could result in damage to igniter
and/or ignition coil.
wAs some tachometers are not compatible
with this ignition system, we recommended
that you confirm compatibility of your unit
before use.
Proceed to matrix chart of problem symptoms
on page EG1±327.
Proceed to page IG±19, 38* and continue
to troubleshoot.
Proceed to matrix chart of problem
symptoms on page EG1±327.
*Except California specification vehicles. Check ignition timing.
Check idle speed.
Check idle speed.
Idle speed: 700 ~ 800 rpm
Check ignition timing.
Ignition timing: 10
BTDC at idle
± 5S±FE ENGINEBASIC INSPECTIONEG1±311

Disconnect the EFI fuse (15A) for 10 sec. or more, with IG switch OFF.
Initiate test mode (Connect terminal TE2 and E1 of data link connector 1 or 2 with IG switch
OFF).
Start the engine and warm up with all ACC switch OFF.
After the engine is warmed up, let it idle for 3 min.
After performing the idling in (3) , perform gradual acceleration with in the range
1,300~1,700 rpm (centered around 1,500 rpm) with the A/C switch ON and D position for A/T
(5th for M /T).
(Take care that the engine speed does not fall below 1,200 rpm when shifting. Gradually
depress the accelerator pedal and keep it. Steady so that engine braking does not occur).
Maintain the vehicle speed at 40 ± 50 mph (64 ± 80 km/h).
Keep the vehicle running for 1 ± 2 min. after starting acceleration.
HINT: If a malfunction exists, the malfunction indicator lamp will light up after approx.
60 sec. from the start of acceleration.
NOTICE: If the conditions in this test are not strictly followed, detection of the mal-
function will not be possible.
CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSIS TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is
recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diag-
nostic trouble code is no longer detected.
Malfunction: Main Oxygen Sensor Deterioration
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±353

H I NT: Before this test, check the feedback voltage for oxygen sensor.
Disconnect the EFI fuse (15 A) for 10 sec. or more, with IG switch OFF.
Initiate test mode (Connect terminal TE2 and E1 of data link connector 1 or 2 with
IG switch OFF).
Start engine and warm up.
After the engine is warmed up, let it race at 2,500 rpm for 3 min.
After performing the racing in (3) , perform idling 1 min.
HINT: If a malfunction exists, the malfunction indicator lamp will light up during step (4).
NOTICE: If the conditions in this test are not strictly followed, detection of the malfunction
will not be possible.
CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSIS TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diagnostic
trouble code is no longer detected.
Malfunction: Open or Short in Main Oxygen Sensor.
Open or Short in Injector Circuit, Injector Leak or Blockage.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±364

Disconnect the E F I fuse (15 A) for 10 sec. or more, with IG switch OFF.
Initiate test mode (Connect terminals TE2 and E1 of data link connector 1 or 2
with I G switch OFF).
Start the engine and warm up, with all ACC switch OFF.
After the engine is warmed up, let it drive at 50 ~ 55 mph (80 ~ 88 km/h)
for 10 min. or more.
After driving, stop at a safe place and perform idling for 2 min. or less.
After performing the idling in (4) , perform acceleration to 60 mph (96 km/h)
with the throttle valve fully open.
HINT: If a malfunction exists, the malfunction indicator lamp will light up during
step.
NOTICE: If the conditions in this test are not strictly followed, detection of the
malfunction will not be possible.
CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSIS TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is
recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diagnos±
tic trouble code is no longer detected.
Malfunction: Open or Short in Sub Oxygen Sensor
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±370

If the ECM detects the above diagnosis conditions, it operates the fail safe function in which the
corrective retard angle value is set to the maximum value.
DIAGNOSIS TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is
recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diag-
nostic trouble code is no longer detected.
Start engine and warm up.
After engine is warmed up, let it idle for 3 min.
With the A/C ON, perform quick racing (5,000 rpm) 3 times.
(Rapidly depress the accelerator pedal and suddenly release it.)
HINT: If a malfunction exists, the malfunction indicator lamp will light up when sudden
racing is performed.
NOTICE: If the conditions in this test are not strictly followed, detection of the mal-
function will not be possible.
CIRCUIT DESCRIPTION
Knock sensor is fitted the cylinder block to detect engine knocking. This sensor contains a piezoelec-
tric element which generates a voltage when it becomes deformed, which occurs when the cylinder
block vibrates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it.
w
Open or short in knock sensor circuit.
wKnock sensor (looseness)
wECM Open or short in knock sensor circuit with engine
speed between 1,200 rpm and 6,000 rpm.
Malfunction: Open or Short in Knock Sensor
Diagnostic Trouble Code Detecting Condition
Trouble Area
DTC 52 Knock Sensor Circuit
DTC No.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±385

Disconnect the EFI fuse (15 A) for 10 sec. or more, with IG switch OFF. Initiate
test mode (Connect terminals TE2 and E1 of data link connector, 1 or 2 with IG
switch OFF).
CIRCUIT DESCRIPTION (Cont'd)
DIAGNOSIS TROUBLE CODE DETECTION DRIVING PATTERN
Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is
recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diag-
nostic trouble code is no longer detected.
Malfunction: Open in EGR gas temp. sensor circuit
Start the engine and warm up.
After the engine is warmed up, let it idle for 3 min.
With the A/C ON and transmission in 5th gear A/T in ªDº position), drive at
55 ± 60 mph (88 ± 96 km/h) for 4 min. or less.
HINT: If a malfunction exists, the malfunction indicator lamp will light up dur-
ing step (4) .
NOTICE: If the conditions in this test are not strictly observed, detection of
the malfunction will not be possible.
± 5S±FE ENGINECIRCUIT INSPECTIONEG1±391