1999 TOYOTA CAMRY Engine idle speed

± DIAGNOSTICSENGINE (5S±FE)
DI±175
410 Author: Date:
DTC P1780 Park/Neutral Position Switch Malfunction
(Only for A/T)
CIRCUIT DESCRIPTION
The park/neutral position switch goes on when the shift lever is in the N or P shift position. When it goes on
terminal NSW of the ECM is grounded to body ground via the starter relay thus the terminal NSW voltage
becomes 0V. When the shift lever is in the D, 2, L or R position, the park/neutral position switch goes off,
so the voltage of ECM. Terminal NSW becomes battery positive voltage, the voltage of the ECM internal
power source.
If the shift lever is moved from the N position to the D position, this signal is used for air±fuel ratio correction
and for idle speed control (estimated control), etc.

DTC No.DTC Detecting ConditionTrouble Area
2 or more switches are ON simultaneously for P, R, N, D, 2
and L positions
(2 trip detection logic)
Sh t i k/ t l iti it h i it
P1780When driving under conditions (a) and (b) for 30 sec. or more
park/neutral position switch is ON (N position):
(2 trip detection logic)
(a) Vehicle speed: 80 km/h (50 mph) or more
(b) Engine speed: 2,000 ~ 5,000 rpm
Short in park/neutral position switch circuit

Park/neutral position switch

ECM
HINT:
After confirming DTC P1780, use the TOYOTA hand±held tester to confirm the PNP switch signal from the
CURRENT DATA.
WIRING DIAGRAM
Refer to DTC P1780 on page DI±424.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
Refer to DTC P1780 on DI±424.
DI01J±05

DI079±02
ENGINE CONTROL SYSTEM Check Sheet
Customer's Name
Driver's Name
Date Vehicle
Brought in
License No.
Model and Model
Year
Frame No.
Engine Model
Odometer Reading
Problem Symptoms
Engine does
not Start
Difficult to
Start
Poor Idling
Poor
Driveability
Engine Stall
Others
Engine does not crankNo initial combustionNo complete combustion
Engine cranks slowly
Other
Incorrect first idleIdling rpm is abnormalHigh ( rpm)Low ( rpm)
Rough idling
Other
HesitationBack fireMuffler explosion (after±fire)Surging
Knocking
Other
Soon after startingAfter accelerator pedal depressed
After accelerator pedal released
During A/C operation
Shifting from N to D
Other
Dates Problem
Occurred
Problem Frequency
Condition When
Problem Occurs
Weather
Engine Operation
Engine Temperature Place Outdoor
TemperatureConstant
Sometimes ( times per day/month)Once only
Other
Fine
CloudyRainySnowyVarious/Other
Hot
Warm CoolCold (approx. °F/ °C)
Highway
SuburbsInner cityUphillDownhill
Rough road
Other
Cold
Warming upAfter warming upAny temperatureOther
Starting
Just after starting ( min.)IdlingRacing
Driving
Constant speedAccelerationDeceleration
A/C switch ON/OFF
Other
Condition of MILRemains on Sometimes light up Does not light up
NormalMalfunction code(s) (code )
Freezed frame data ( )
NormalMalfunction code(s) (code )
Freezed frame data ( )
Normal Mode
(Precheck)
Check Mode DTC InspectionInspector's
Name
km
miles
DI±196
± DIAGNOSTICSENGINE (1MZ±FE)
431 Author: Date:
CUSTOMER PROBLEM ANALYSIS CHECK

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.

DI±214
± DIAGNOSTICSENGINE (1MZ±FE)
449 Author: Date:
DTC No.
(See Page)Detection ItemTrouble AreaMIL*Memory
P0440
(DI±311)Evaporative Emission Control
System Malfunction
Vapor pressure sensor
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or
disconnected ((1) or (2) in fig. 1)
Hose or tube cracked, holed, damaged or loose seal
((3) in fig. 1)
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked or damaged
*1
P0441
(DI±318)Evaporative Emission Control
System Incorrect Purge Flow
Open or short in VSV circuit for EVAP
Open or short in VSV circuit for vapor pressure sensor
Open or short in vapor pressure sensor circuit
VSV for EVAP
VSV for vapor pressure sensor
Vapor pressure sensor
Vacuum hose cracks, holed blocked, damaged or
disconnected ((1), (4), (5), (6) and (7) in fig.1)
Charcoal canister cracks, holed or damaged
Fuel tank over fill check valve cracked or damaged

P0446
(DI±318)Evaporative Emission Control
System Vent Control
Malfunction
Open or short in VSV circuit for EVAP
Open or short in VSV circuit for vapor pressure sensor
Open or short in vapor pressure sensor circuit
VSV for EVAP
VSV for vapor pressure sensor
Vapor pressure sensor
Vacuum hose cracks, holed blocked, damaged or
disconnected ((1), (4), (5), (6) and (7) in fig.1)
Charcoal canister cracks, holed or damaged
Fuel tank over fill check valve cracked or damaged

P0450
(DI±331)Evaporative Emission Control
System Pressure Sensor
MalfunctionOpen or short in vapor pressure sensor circuit
Vapor pressure sensor
ECM

P0451
(DI±331)Evaporative Emission Control
System Pressure Sensor
Range/PerformanceOpen or short in vapor pressure sensor circuit
Vapor pressure sensor
ECM

P0500
(DI±333)Vehicle Speed Sensor
Malfunction
Open or short in speed sensor circuit
Vehicle speed sensor
Combination meter
ECM

P0505
(DI±336)Idle Control System
Malfunction
IAC valve is stuck or closed
Open or short in IAC valve circuit
Open or short in A/C signal circuit
Air intake (hose loose)

*: 


MIL lights up

DI07E±06
± DIAGNOSTICSENGINE (1MZ±FE)
DI±221
456 Author: Date:
PROBLEM SYMPTOMS TABLE
SymptomSuspect AreaSee page
Engine does not crank (Does not start)1. Starter
2. Starter relayST±18
ST±20
No initial combustion (Does not start)
1. ECM power source circuit
2. Fuel pump control circuit
3. Engine control module (ECM)DI±369
DI±374
IN±31
No complete combustion (Does not start)1. Fuel pump control circuitDI±374
Engine cranks normally (Difficult to start)
1. Starter signal circuit
2. Fuel pump control circuit
3. CompressionDI±384
DI±374
EM±3
Cold engine (Difficult to start)1. Starter signal circuit
2. Fuel pump control circuitDI±384
DI±374
Hot engine (Difficult to start)1. Starter signal circuit
2. Fuel pump control circuitDI±384
DI±374
High engine idle speed (Poor idling)1. A/C signal circuit (Compressor Circuit)
2. ECM power source circuitAC±88
DI±369
Low engine idle speed (Poor idling)1. A/C signal circuit (Compressor Circuit)
2. Fuel pump control circuitAC±88
DI±374
Rough idling (Poor idling)1. Compression
2. Fuel pump control circuitEM±3
DI±374
Hunting (Poor idling)1. ECM power source circuit
2. Fuel pump control circuitDI±369
DI±374
Hesitation/Poor acceleration (Poor driveability)1. Fuel pump control circuit
2. A/T faultyDI±374
DI±453
Surging (Poor driveability)1. Fuel pump control circuitDI±374
Soon after starting (Engine stall)1. Fuel pump control circuitDI±374
During A/C operation (Engine stall)1. A/C signal circuit (Compressor Circuit)
2. Engine control module (ECM)AC±88
IN±31
Unable to refuel/Difficult to refuel1. ORVR systemEC±6

A01666
Vehicle speed
50 ~ 65 km/h
(31 ~ 40 mph)
(5)Idling
IG SW OFF
1 ~ 3 min. 1 min.Time
(2)
(1)(3)(4)
± DIAGNOSTICSENGINE (1MZ±FE)
DI±255
490 Author: Date:
DTC P0130 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1) (Except California Spec.)
DTC P0150 Heated Oxygen Sensor Circuit Malfunction
(Bank 2 Sensor 1) (Except California Spec.)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI±244.
DTC No.DTC Detecting ConditionTrouble Area
P0130
P0150Voltage output of heated oxygen sensor remains at 0.4 V or
more, or 0.55 V or less, during idling after engine is warmed up
(2 trip detection logic)
Heated oxygen sensor

Fuel trim malfunction
HINT:
Bank 1 refers to the bank that includes cylinder No.1. Bank 2 refers to the bank that does not include cylinder
No.1. Sensor 1 refers to the sensor closer to the engine body.
The heated oxygen sensor's output voltage and the short-term fuel trim value can be read using the
OBD II scan tool or TOYOTA hand-held tester.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI±244.
CONFIRMATION DRIVING PATTERN
(1) Connect the TOYOTA hand±held tester to the DLC3.
(2) Switch the TOYOTA hand±held tester from normal mode to check mode (See page DI±197).
(3) Start the engine and warm it up with all accessory switches OFF.
(4) Drive the vehicle at 50 ~ 65 km/h (31 ~ 40 mph) for 1 ~ 3 min. to warm up the heated oxygen sensor.
(5) Let the engine idle for 1 min.
(6) Perform steps (3) to (5) three times.
DI07N±07

P01559
Throttle Valve
From
Air
Cleaner
Signal
ECM
ValveIAC Valve
To Cylinders Intake Air Chamber
A07448
From
BatteryFL
MAIN
EC
F4 F611Fusible
Link
Block
B1
7 2
5EFI Engine Room J/B
EFI Relay1
23
5 2A
2K 2J
2C W±BIAC Valve
J27J28
B±Y
9II3
21
3E1116
15ECM
RSO
E01
RSC
E01 AA
B±W
MREL
B+ E11
E78
B±G
BB±YB±Y
J36
J35 AC J16
Junction
Connector
B±YR±W
Y±B
B±W
Junction
ConnectorB
Junction
Connector B DI±336
± DIAGNOSTICSENGINE (1MZ±FE)
571 Author: Date:
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located in front of the in-
take air chamber and intake air bypassing the throttle valve is
directed to the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle±up and
provide feedback for the target idling speed.
DTC No.DTC Detecting ConditionTrouble Area
P0505Idle speed continues to vary greatly from target speed
(2 trip detection logic)

IAC valve is stuck or closed

Open or short in IAC valve circuit

Open or short in A/C signal circuit

Air intake (hose loose)

ECM
WIRING DIAGRAM
DI083±06

± DIAGNOSTICSENGINE (1MZ±FE)
DI±337
572 Author: Date:
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check engine idle speed.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off air conditioning.
(d) Shift transmission into ºNº or neutral position.
(e) Connect the OBD II scan tool or TOYOTA hand±held tester to DLC3 on the vehicle.
(f) Using SST, connect terminals TE1 and E1 of the DLC3.
CHECK:
Check the difference of engine speed between the ones less than 5 sec. and more than 5 sec. after connect-
ing terminals TE1 and E1 of the DLC1.
OK:
Difference of engine speed: More than 100 rpm
OK Go to step 6.
NG