1999 TOYOTA CAMRY ESP

2. CONTROL SYSTEM
*SFI system
The SFI system monitors the engine condition through the signals, which are input from each sensor (Input signals from
(1) to (14) etc.) to the engine control module. The best fuel injection volume is decided based on this data and the
program memorized by the engine control module, and the control signal is output to TERMINALS #10, #20, #30 and
#40 of the engine control module to operate the injector. (Inject the fuel). The SFI system produces control of fuel
injection operation by the engine control module in response to the driving conditions.
*ESA system
The ESA system monitors the engine condition through the signals, which are input to the engine control module from
each sensor (Input signals from (1), (2), (4) to (12) etc.) the best ignition timing is detected according to this data and the
memorized data in the engine control module, and the control signal is output to TERMINALS IGT1 and IGT2. This
signal controls the igniter to provide the best ignition timing for the driving conditions.
*Idle Air Control system
The IAC system (Step motor type) increases the RPM and provides idling stability for fast idle±up when the engine is
cold and when the idle speed has dropped due to electrical load, etc. The engine control module evaluates the signals
from each sensor (Input signals (1), (4) to (8), (13) etc.), outputs current to TERMINALS ISCO and ISCC, and controls
the idle air control valve.
*Fuel pump control system
The engine control module operation outputs to TERMINAL FC and controls the CIR OPN relay. Thus controls the fuel
pump drive speed in response to conditions.
*EGR control system
The EGR cut control system controls the VSV (EGR) by evaluating the signals from each sensor which are input to the
engine control module (Input signals (1), (5), (6), (9) etc.) and by sending output to TERMINAL EGR of the engine
control module.
*A/C conditioning operation system
In addition to the conventional A/C cut control, the engine control module performs the air conditioning operation as well
since the A/C amplifier function is built in it.
3. DIAGNOSIS SYSTEM
With the diagnosis system, when there is a malfunctioning in the engine control module signal system, the malfunction
system is recorded in the memory. The malfunctioning system can then be found by reading the display (Code) of the
malfunction indicator lamp.
4. FAIL±SAFE SYSTEM
When a malfunction occurs in any system, if there is a possibility of engine trouble being caused by continued control based
on the signals from that system, the fail±safe system either controls the system by using data (Standard values) recorded in
the engine control module memory or else stops the engine.
E7 (A), E8 (B), E9 (C), E10 (D) ENGINE CONTROL MODULE
Voltage at engine control module wiring connector
BATT±E1 : Always 9.0±14.0 volts
+B±E1 :9.0±14.0 volts (Ignition SW at ON position)
VC±E2 :4.5± 5.5 volts (Ignition SW at ON position)
VTA±E2 :0.3± 0.8 volts (Ignition SW on and throttle valve fully closed)
3.2±4.9 volts (Ignition SW on and throttle valve open)
PIM±E2 :3.3± 3.9 volts (Ignition SW at ON position)
THA±E2 :0.5±3.4 volts (Ignition SW on and intake air temp. 20°C, 68°F)
THW±E2 :0.2± 1.0 volts (Ignition SW on and coolant temp. 80°C, 176°F)
STA±E1 :6.0±14.0 volts (Engine cranking)
W±E1 :9.0±14.0 volts (No trouble and engine running)
TE1±E1 :9.0±14.0 volts (Ignition SW at ON position)
NSW±E1 :0± 3.0 volts (Ignition SW on and Park/Neutral position SW position P or N position)
9.0±14.0 volts (Ignition SW on and except Park/Neutral position SW position P or N position)
IGT1, IGT2±E1 : Pulse generation (Engine cranking or idling)
#10, #20, #30, #40±E01, E02 :9.0±14.0 volts (Ignition SW at ON position)
RESISTANCE AT ENGINE CONTROL MODULE WIRING CONNECTORS
(Disconnect wiring connector)
VC±E2 :2.5±5.0 kW
THA±E2 :2.21±2.69 kW (Intake air temp. 20°C, 68°F)
THW±E2 :0.29±0.354 kW (Coolant temp. 80°C, 176°F)
SERVICE HINTS

7. TAP±UP CONTROL FUNCTION
When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be
increased 1.6 km/h (1 mph) each time by operation the RESUME/ACCEL SW quickly within 0.6 seconds.
8. TAP±DOWN CONTROL FUNCTION
When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be
lowered 1.6 km/h (1 mph) each time by operating the SET/COAST SW quickly within 0.6 seconds.
9. AUTO CANCEL FUNCTION
A) If any of the following operating conditions occurs during cruise control operation, the set speed is erased, the current
flow to the magnetic clutch is stopped and the cruise control is released. (Cruise SW turns off).
When this occurs, the ignition SW must be turned off once before the cruise SW will turn on.
*When current continued to flow to the motor inside the actuator in the throttle valve ºOPENº direction.
*The motor does not operate despite the motor drive signal being output.
B) If any of the following operating conditions occurs during cruise control operation, the set speed is erased, the current
flow to the magnetic clutch is stopped and the cruise control is released. (Cruise SW turn off).
When this occurs, the cancel state is cleared as the cruise SW will turn on again.
*Over current to transistor driving the motor and/or the magnetic clutch.
*Open circuit in the magnetic clutch.
*Momentary interruption of vehicle speed signal.
*Short circuit in the cruise control SW.
*When the vehicle speed falls more than 16 km/h (10 mph) below the set speed, E.G. on an upward slope.
C) If any of the following conditions occurs during cruise control operation, the set speed is erased and the cruise control is
released. (The power to the magnetic clutch is cut off until the set SW is ON again.)
*When the vehicle speed falls below the minimum speed limit, approx. 40 km/h (25 mph).
*When power to the cruise control system is momentarily cut off.
D) If any of the following conditions occurs during cruise control operation, the cruise control is released.
*Open the circuit for TERMINAL 2 of the stop light SW.
10. AUTOMATIC TRANSAXLE CONTROL FUNCTION
*In overdrive. If the vehicle speed becomes lower than the overdrive cut speed (Set speed minus approx. 4 km/h, 2.5 mph)
during cruise control operation, such as driving up a hill, the overdrive is released and the power increased to prevent a
reduction in vehicle speed.
*After releasing the overdrive, vehicle speed becomes higher than the overdrive return speed (Set speed minus approx. 2
km/h, 1.2 mph) and the cruise control ECU judges by the signals from the actuator's potentiometer that the upward slope
has finished, the overdrive is resumed after approximately 2 seconds.
*During cruise control driving, the cruise control operation signal is output from the cruise control ECU to the engine control
module. Upon receiving this signal, the engine control module changes the shift pattern to normal.
To maintain smooth cruise control operation (on a downward slope etc.), the lock±up release of the transmission when the
idling point of the throttle position is ON is forbidden.
C3 CRUISE CONTROL ACTUATOR
3±4 : Approx. 38.5 W
C12 CRUISE CONTROL SW [COMB. SW]
5±3 : Continuity with the CRUISE SW on
4±3 : Approx. 418 W with the CANCEL SW on
Approx. 68 W with the RESUME/ACCEL SW on
Approx. 198 W with the SET/COAST SW on
C15 CRUISE CONTROL ECU
9±GROUND :10±14 volts with the ignition SW at ON position
12±GROUND :4 pulses with 1 rotation of rotor shaft
10±GROUND : Approx. 418 W with the CANCEL SW on in the cruise control SW
Approx. 198 W with the SET/COAST SW on in the cruise control SW
Approx. 68 W with the RESUME/ACCEL SW on in the cruise control SW
16±GROUND : Always continuity
SERVICE HINTS

ABS (TMC MADE)
This system controls the respective brake fluid pressures acting on the disc brake cylinders of the right front wheel, left front
wheel and rear wheels when the brakes are applied in a panic stop so that the wheels do not lock. This results in improved
directional stability and steerability during panic braking.
1. INPUT SIGNALS
(1) Speed sensor signal
The speed of the wheels is detected and input to TERMINALS FL+, FR+, RL+ and RR+ of the ABS ECU.
(2) Stop light SW signal
A signal is input to TERMINAL STP of the ABS ECU when the brake pedal is depressed.
2. SYSTEM OPERATION
During sudden braking the ABS ECU has signals input from each sensor, which controls the current to the solenoid inside
the actuator and lets the hydraulic pressure acting on each wheel cylinder escape to the reservoir. The pump inside the
actuator is also operating at this time and it returns the brake fluid from the reservoir to the master cylinder, thus preventing
locking of the vehicle wheels.
If the ABS ECU judges that the hydraulic pressure acting on the wheel cylinder is insufficient, the current on the solenoid is
controlled and the hydraulic pressure is increased. Holding of the hydraulic pressure is also controlled by the ABS ECU, by
the same method as above. Pressure reduction, holding and increase are repeated to maintain vehicle stability and to
improve steerability during sudden braking.
A9, A10 ABS SPEED SENSOR FRONT LH, RH
2±1 :0.6 kW±2.5 kW
A25, A26 ABS SPEED SENSOR REAR LH, RH
2±1 :1.2 kW±2.3 kW
A18 (A), A19 (B) ABS ECU
(Connect the ABS ECU connectors)
(B)21±GROUND : Approx. 12 volts with the ignition SW at ON position and the data link connector 1
TS±E1, TC±E1 not connected
(B) 8±GROUND : Approx. 12 volts with the ignition SW at ON position and the data link connector 1
TS±E1, TC±E1 not connected
(B)13±GROUND : Approx. 12 volts with the ignition SW at ON position
(B) 5±GROUND : Approx. 12 volts with the brake pedal depressed
(B)12, (B) 25±GROUND :
Always continuity
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
A4A26 (1MZ±FE)A2532J1131A4A28 (5S±FE)A2632J1231
A5B26 (1MZ±FE)C1030J2231A5B28 (5S±FE)D126 (1MZ±FE)J2331
A926 (1MZ±FE)D128 (5S±FE)J27A31A928 (5S±FE)D430J28B31
A1026 (1MZ±FE)J331J2931A1028 (5S±FE)J431S631
A18A30J7A31
A19B30J8B31
: RELAY BLOCKS
CodeSee PageRelay Blocks (Relay Block Location)
325Engine Room R/B No.3 (Radiator Upper Support RH)
SYSTEM OUTLINE
SERVICE HINTS

ABS (TMMK MADE)
This system controls the respective brake fluid pressures acting on the disc brake cylinders of the right front wheel, left front
wheel and rear wheels when the brakes are applied in a panic stop so that the wheels do not lock. This results in improved
directional stability and steerability during panic braking.
1. INPUT SIGNALS
(1) Speed sensor signal
The speed of the wheels is detected and input to TERMINALS FL+, FR+, RL+ and RR+ of the ABS actuator and ECU.
(2) Stop light SW signal
A signal is input to TERMINAL STP of the ABS actuator and ECU when the brake pedal is depressed.
2. SYSTEM OPERATION
During sudden braking the ABS actuator and ECU has signals input from each sensor, which controls the current to the
solenoid inside the actuator and lets the hydraulic pressure acting on each wheel cylinder escape to the reservoir. The pump
inside the actuator is also operating at this time and it returns the brake fluid from the reservoir to the master cylinder, thus
preventing locking of the vehicle wheels.
If the ABS actuator and ECU judges that the hydraulic pressure acting on the wheel cylinder is insufficient, the current on the
solenoid is controlled and the hydraulic pressure is increased. Holding of the hydraulic pressure is also controlled by the
ABS actuator and ECU, by the same method as above. Pressure reduction, holding and increase are repeated to maintain
vehicle stability and to improve steerability during sudden braking.
A9, A10 ABS SPEED SENSOR FRONT LH, RH
2±1 : Approx. 1.6 kW
A25, A26 ABS SPEED SENSOR REAR LH, RH
2±1 : Approx. 1.6 kW
A6 ABS ACTUATOR AND ECU
(Connect the ABS actuator and ECU connectors)
12±GROUND : Approx. 12 volts with the ignition SW at ON position and the data link connector 1
TS±E1, TC±E1 not connected
11±GROUND : Approx. 12 volts with the ignition SW at ON position and the data link connector 1
TS±E1, TC±E1 not connected
16, 19±GROUND : Always continuity
15±GROUND : Approx. 12 volts with the ignition SW at ON position
14±GROUND : Approx. 12 volts with the brake pedal depressed
17, 18±GROUND : Always approx. 12 volts
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
A626 (1MZ±FE)C1030J1231A628 (5S±FE)D126 (1MZ±FE)J2231
A926 (1MZ±FE)D128 (5S±FE)J2331A928 (5S±FE)D430J27A31
A1026 (1MZ±FE)J331J28B31A1028 (5S±FE)J431J2931
A2532J7A31S631
A2632J8B31
: RELAY BLOCKS
CodeSee PageRelay Blocks (Relay Block Location)
325Fusible Link Block (Radiator Upper Support RH)
SYSTEM OUTLINE
SERVICE HINTS