Ecm TOYOTA CAMRY 2000 Service Owner's Manual

ENGINE CONTROL MODULE (ECM)
ECM REMOVAL AND INSTALLATION
ECM INSPECTION
(See page EG1±318)
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±234

HOW TO PROCEED WITH TROUBLESHOOTING
The Engine Control System broadly consists of the sensors, Engine Control Module (ECM) and actuators.
The ECM receives signals from various sensors, judges the operating conditions and determines the
optimum injection duration, timing, ignition timing and idle speed.
In general, the Engine Control System is considered to be a very intricate system to troubleshoot. But, the
fact is that if you proceed to inspect the circuit one by one following the procedures directed in this manu-
al, troubleshooting of this system is not complex.
This section explains the most ideal method of troubleshooting and tells how to carry out the necessary
repairs.
1. CUSTOMER PROBLEM ANALYSIS
Using the customer problem analysis check sheet for reference, ask the customer in as much details
as possible about the problem.
2. CHECK AND CLEAR DIAGNOSTIC TROUBLE CODE (PRECHECK)
Before confirming the problem symptom, first check the diagnostic trouble code and make a note of
any malfunction code which is output, then clear the code.
HINT: Output of the malfunction code indicates that there is a malfunction in the circuit indicated.
However, it does not indicate whether the malfunction is still occurring or occurred in the past and
returned to normal. In order to determine this, the problem sym toms should be confirmed in step 4
first and the diagnostic trouble code be rechecked in step [6].
Accordingly, if troubleshooting is begun based on the malfunction code only in diagnostic trouble
code check in step [2], it could result in a misdiagnosis, leading to troubleshooting of circuits which
are normal and making it more difficult to locate the cause of the problem.
3. SETTING THE TEST MODE DIAGNOSIS, [4] PROBLEM SYMPTOM CONFIRMATION,
[5] SYMPTOM SIMULATION
In order to find out the trouble more quickly, set the diagnosis check in test mode and with higher
sensing ability of the ECM, confirm the problem symptoms. If the trouble does not reappear, use the
symptom simulation method to make sure the trouble is reproduced.
6. DIAGNOSTIC TROUBLE CODE CHECK IN TEST MODE
Check the diagnostic trouble code in test mode. If the malfunction code is output, proceed to step. If the
normal code is output, proceed to step [7].
7. BASIC INSPECTION
Carry out basic inspection such as the spark check and fuel pressure check, etc.
8. DIAGNOSTIC TROUBLE CODE CHART
If the malfunction code is displayed, proceed to inspect the circuit indicated by the chart for each
code.
9. MATRIX CHART OF PROBLEM SYMPTOMS
If the normal code is displayed in the diagnosis in test mode, perform troubleshooting according to
the inspection order in the Matrix Chart of Problem Symptoms.
10. PARTS INSPECTION
When the Matrix Chart of Problem Symptoms instructs to check the parts, proceed to parts inspection
section included in this manual.
11. CIRCUIT INSPECTION
Determine if the malfunction is the sensor, actuator, wire harness, connector or the ECM.
± 5S±FE ENGINEHOW TO PROCEED WITH TROUBLESHOOTINGEG1±292

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

ECM DATA MONITOR USING TOYOTA
HAND±HELD TESTER
1. Hook up the TOYOTA hand±held tester to the D LC2.
2. Monitor the ECM data by following the prompts on the
tester screen.
HINT: TOYOTA hand±held tester has a ªSnapshotº
function which records the monitored data.
Please refer to the TOYOTA hand±held tester operator's
manual for further details.
ECM TERMINAL VALUES MEASUREMENT
USING TOYOTA BREAK±OUT±BOX AND
TOYOTA HAND±HELD TESTER
1. Hook up the TOYOTA break±out±box and TOYOTA
hand±held tester to the vehicle.
2. Read the ECM input/output values by following the
prompts on the tester screen.
HINT: TOYOTA hand±held tester has ªSnapshotº func±
tion. This records the measured values and is effective in
the diagnosis of intermittent problems.
Please refer to the TOYOTA hand±held tester/Toyota
break±out±box operator's manual for further details.
DIAGNOSTIC TROUBLE CODE CLEARANCE
1. After repair of the trouble areas, the diagnostic trouble
code retained in the ECM memory must be cleared out by
removing the E F I fuse (15A) from J/13 No. 2 for 10 seconds or
more, with the ignition switch OFF.
HINT:
wCancellation can also be done by removing the battery
negative (±) terminal, but in this case, other memory
systems (clock, etc.) will also be cancelled out.
wIf it is necessary to work on engine components requir±
ing removal of the battery terminal, a check must first
be made to see if a diagnostic trouble code has been
recorded.
2. After cancellation, road test the vehicle to check that a
normal code is now read on the malfunction indicator
lamp.
If the same diagnostic trouble code appears, it indicates
that the trouble area has not been repaired thoroughly.
DIAGNOSTIC TROUBLE CODE CHECK
USING TOYOTA HAND±HELD TESTER
1. Hook up the TOYOTA hand±held tester to the DLC2.
2. Read the diagnostic trouble codes by following the
prompts on the tester screen.
Please refer to the TOYOTA hand±held tester operator's
manual for further details.
± 5S±FE ENGINEDIAGNOSIS SYSTEMEG1±299

DIAGNOSTIC TROUBLE CODE CHART
HINT: Parameters listed in the chart may not be exactly same as your reading due to type of the in-
struments or other factors.
No G signal to ECM while NE signal is input 4 times to ECM when
engine speed is between 500 rpm and 4,000 rpm.No G signal to ECM for 3 sec. or more with engine speed between
600 rpm and 4,000 rpm.
* NE signal does not pulse 12 times to ECM during the interval
between G1 and G2 pulses.
Fault in communications between the engine CPU and A/T CPU
in the ECMNo N E or G 1 and G2 signal to ECM for 2 sec. or more after
cranking.
* No N E signal to ECM for 0.1 sec. or more at 1,000 rpm or more. No NE signal to ECM for 0.3 sec. or more at 1,500 rpm or more.No NE signal to ECM within 2 sec. or more after cranking.
* No IGF signal to ECM for 8 consecutive IGT signals. No IGF signal to ECM for 4 consecutive IGT signals. G, N E Signal
Circuit (No. 1)
(Only for
California spec,) G, NE Signal
Circuit (No. 1)
(Exc. California
spec.)Diagnostic Trouble Code
Detecting Condition
G, NE Signal
Circuit (No. 2)
Ignition Signal
Circuit
*,* : See page EG1±306A/T Control
SignalOpen in G (±) circuit Number of
MIL Blinks
No code is recorded. DTC
No.Circuit
Normal
± 5S±FE ENGINEDIAGNOSTIC TROUBLE CODE CHARTEG1±300

If a malfunction code is displayed during the diagnostic trouble code check in test mode, check the circuit
for that code listed in the table below (Proceed to the page given for that circuit).
wOpen or short in IGF or IGT circuit from igniter to ECM
wIgniter
wECM wOpen or short in NE, G circuit
wDistributor
wOpen or short in STA circuit
9 ECM
wOpen or short in NE circuit
wDistributor
wECM
Malfunction
Indicator
Lamp*

*
,*: See page EG1±306Normal
Mode Trouble Area
Memory*
Test
ModeSee page
EG1±351EG1±339
wECM
E G ±343 EG1±336
EG1±344 N.A.
N.A.N.A.
N.A. N.A.
N.A.N.A.
± 5S±FE ENGINEDIAGNOSTIC TROUBLE CODE CHARTEG1±301

wOpen or short in injector circuit
wFuel line pressure (injector leak, blockage)
wMechanical system malfunction (skipping teeth of timing
belt)
wIgnition system
w Compression pressure (foreign object caught in valve)
wAir leakage
wECM wOpen or short in main oxygen sensor circuit
wMain oxygen sensor
wignition system
wECM wOpen or short in engine coolant temp. sensor circuit
wEngine coolant temp. sensor
wECM
wOpen or short in intake air temp. sensor circuit
wIntake air temp. sensor
wECM wMain oxygen sensor circuit
w Main oxygen sensorMalfunction
Indicator
Lamp*

*
,*: See page EG1±306Normal
Mode Trouble AreaMemory`
Test
ModeSee page
EG1±360
EG1±363EG1±352
EG1±356
± 5S±FE ENGINEDIAGNOSTIC TROUBLE CODE CHARTEG1±303

wOpen or short in injector circuit
wFuel line pressure (injector leak, blockage)
wMechanical system malfunction (skipping teeth of timing
belt)
wIgnition system
wCompression pressure (foreign object caught in valve)
wAir leakage
w ECM
wOpen or short in No.1 vehicle speed sensor circuit
wNo.1 vehicle speed sensor
wCombination meter
wECM wOpen or short in manifold absolute pressure sensor circuit.
wManifold absolute pressure sensor
wECM
wOpen or short in throttle position sensor circuit
wThrottle position sensor
wECM wOpen or short in sub oxygen sensor circuit
wSub oxygen sensor
wECMMalfunction
Indicator
Lamp*

*
,*: See page EG1±306Normal
Mode Trouble Area
Memory*
Test
ModeSee page
EG1±380EG1±369
EG1±376EG1±372EG1±363
OFF OFF
± 5S±FE ENGINEDIAGNOSTIC TROUBLE CODE CHARTEG1±305

*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

*5: This indicates items for which ª2 trip detection logicº is used. With this logic, when a logic malfunction is first detected, the
malfunction is temporarily stored in the ECM memory. If the same case is detected again during the second drive test, this
second detection causes the Malfunction Indicator Lamp to light up.
The 2 trip repeats the same mode a 2nd time. (However, the IG switch must be turned OFF between the 1st trip and 2nd
trip),
In the Test Mode, the Malfunction Indicator Lamp lights up the 1st trip a malfunction is detected.wopen in EGR gas temp. sensor circuit
wShort in VSV circuit for EGR
wEGR hose disconnected, valve stuck
wClogged EGR gas passage
wECM
wThrottle position sensor IDL circuit
wAccelerator pedal and cable
wPark/Neutral Position switch circuit
wA/C switch circuit
wECM wOpen or short in starter signal circuit
wOpen or short in ignition switch or starter relay circuit ECM
wOpen or short in knock sensor circuit
wKnock sensor (looseness).
wECMMalfunction
Indicator
Lamp*

Normal
Mode Trouble AreaMemory*
Test
ModeSee page
EG1±390EG1±385
EG1±396EG1±383
N.A.N.A.
N.A.
OFFOFF
± 5S±FE ENGINEDIAGNOSTIC TROUBLE CODE CHARTEG1±307