ABS TOYOTA CAMRY 1999 Service Workshop Manual

BE6653P23721A03008A03407
w/o Immobiliser
w/ ImmobiliserE2 (±)
VC (+)
ON
E2 (±)
VC (+)
± DIAGNOSTICSENGINE (5S±FE)
DI±31
266 Author: Date:
1 Connect OBD II scan tool or TOYOTA hand±held tester, and read value of man-
ifold absolute pressure.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand±held tester main switch
ON.
CHECK:
Read value of the manifold absolute pressure on the OBD II scan tool or TOYOTA hand±held tester.
OK:
Same as atmospheric pressure.
OK Check for intermittent problems
(See page DI±3).
NG
2 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals VC and E2 of the ECM
connector.
OK:
Voltage: 4.5 ± 5.5 V
NG Check and replace ECM (See page IN±31).
OK

BE6653P23722A03009A03408
w/o Immobiliser
w/ ImmobiliserPIM (+)E2 (+)
ON
PIM (+)
E2 (+)
DI±32
± DIAGNOSTICSENGINE (5S±FE)
267 Author: Date:
3 Check voltage between terminals PIM and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals PIM and E2 of the ECM
connector.
OK:
Voltage: 3.3 ± 3.9 V
OK Check and replace ECM (See page IN±31).
NG
4 Check for open and short in harness and connector between manifold absolute
pressure sensor and ECM.
NG Repair or replace harness or connector.
OK
Replace manifold absolute pressure sensor
(See page SF±52).

± DIAGNOSTICSENGINE (5S±FE)
DI±33
268 Author: Date:
DTC P0106 Manifold Absolute Pressure Circuit
Range/Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction) on page
DI±29.
DTC No.DTC Detecting ConditionTrouble Area
P0106
After engine is warmed up, conditions (a) and (b) continue with
engine speed 400 ~ 1,000 rpm
(2 trip detection logic)
(a) Throttle valve fully closed
(b) Manifold absolute pressure sensor output > 3.0 V

Manifold absolute pressure sensorP0106Condition (c) and (d) continue with engine speed 2,500 rpm or
less
(2 trip detection logic)
(c) VTA > 1.85
(d) Manifold absolute pressure sensor output < 1.0 V

Manifold absolute ressure sensor

Vacuum line
WIRING DIAGRAM
Refer to DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction) on page
DI±29.
INSPECTION PROCEDURE
HINT:

If DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction) and P0106 (Man-
ifold Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem) are output simul-
taneously, manifold absolute pressure sensor circuit may be open. Perform troubleshooting of DTC
P0105 first.

If DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Manifold
Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem), P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/
Pedal Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground)
may be open.

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 Are there any other codes (besides DTC P0106) being output?
YES Go to relevant DTC chart.
NO
DI00N±04

DI±34
± DIAGNOSTICSENGINE (5S±FE)
269 Author: Date:
2 Check manifold absolute pressure sensor operation (See page SF±52).
OK Check vacuum line between intake air chamber
and manifold absolute pressure sensor.
NG
Replace manifold absolute pressure sensor.

A00310
Intake Air Temp. Sensor
E8
E83
9ECM
5 V
THA
E2
E1 R
Y±B
BR 2
1 DI±36
± DIAGNOSTICSENGINE (5S±FE)
271 Author: Date:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Man-
ifold Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem), P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/
Pedal Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground)
may be open.

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.

A00310
Engine Coolant Temp.
Sensor
2
1ECM
G±B
BR4
E8
E895 V
THW
E2
E1 R DI±42
± DIAGNOSTICSENGINE (5S±FE)
277 Author: Date:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Man-
ifold Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem), P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/
Pedal Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground)
may be open.

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.

A03595
Throttle Position Sensor
ECM
E8
E8 1
3
2Y
LG
BR1
11
9VC
VTA
E25 V
*1: w/o Immobiliser
*2: w/ Immobiliser(*2)
E8 E810
(*1)
DI±50
± DIAGNOSTICSENGINE (5S±FE)
285 Author: Date:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Man-
ifold Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem), P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/
Pedal Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground)
may be open.

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.

± DIAGNOSTICSENGINE (5S±FE)
DI±79
314 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Only for California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Only for California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short±term fuel trim and long±term fuel trim.
Short±term fuel trim is the short±term fuel compensation used to maintain the air±fuel ratio at its ideal
theoretical value.
The signal from the A/F sensor is approximately proportional to the existing air±fuel ratio, and ECM compar-
ing it with the ideal theoretical value, the ECM reduces fuel volume immediately if the air±fuel ratio is rich
and increases fuel volume if it is lean.
Long±term fuel trim compensates the deviation from the central value of the short±term fuel trim stored up
by each engine tolerance, and the deviation from the central value due to the passage of time and changes
of using environment.
If both the short±term fuel trim and long±term fuel trim exceed a certain value, it is detected as a malfunction
and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air±fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on rich side
(2 trip detection logic)

Gas leakage on exhaust system

Air intake (loose hoses)

Fuel line pressure

Injector blockage

Manifold absolute pressure sensor

Engine coolant temp. sensor

A/F sensor
P0172
When air±fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on lean side
(2 trip detection logic)

Gas leakage on exhaust system

Fuel line pressure

Injector leak, blockage

Manifold absolute pressure sensor

Engine coolant temp. sensor

A/F sensor
HINT:

When the DTC P0171 is recorded, the actual air±fuel ratio is on the lean side. When DTC P0172 is
recorded, the actual air±fuel ratio is on the rich side.

If the vehicle runs out of fuel, the air±fuel ratio is lean and DTC P0171 is recorded. The MIL then comes
on.

If the total of the short±term fuel trim value and long±term fuel trim value is within + 38 %, the system
is functioning normally.

The A/F sensor output voltage and the short±term fuel trim value can be read using the OBD II scan
tool or TOYOTA hand±held tester.

The ECM controls the voltage of AF
and AF terminals of ECM to the fixed voltage. Therefore, it
is impossible to confirm the A/F sensor output voltage without OBD II scan tool or TOYOTA hand±held
tester.
DI1JW±03

DI±80
± DIAGNOSTICSENGINE (5S±FE)
315 Author: Date:

OBD II scan tool (excluding TOYOTA hand±held tester) displays the one fifth of the A/F sensor output
voltage which is displayed on the TOYOTA hand±held tester.
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 airÅfuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check air induction system (See page SF±1).
NG Repair or replace.
OK
2 Check injector injection (See page SF±23).
NG Replace injector.
OK
3 Check manifold absolute pressure sensor and engine coolant temp. sensor
(See pages SF±53 and SF±49).
NG Repair or replace.
OK
4 Check for spark and ignition (See page IG±1).
NG Repair or replace.
OK

DI±84
± DIAGNOSTICSENGINE (5S±FE)
319 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Except California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Except California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short±term fuel trim and long±term fuel trim.
Short±term fuel trim is the short±term fuel compensation used to maintain the air±fuel ratio at its ideal
theoretical value. The signal from the heated oxygen sensor indicates whether the air±fuel ratio is RICH or
LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air±fuel ratio is rich,
and an increase in fuel volume if it is lean.
Long±term fuel trim is overall fuel compensation carried out long±term to compensate for continual deviation
of the short±term fuel trim from the central value due to individual engine differences, wear over time and
changes in the usage environment.
If both the short±term fuel trim and long±term fuel trim are LEAN or RICH beyond a certain value, it is
detected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air±fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on RICH side
(2 trip detection logic)

Gas leakage on exhaust system

Air intake (hose loose)

Fuel line pressure

Injector blockage

Heated oxygen sensor (bank 1 sensor 1)

Manifold absolute pressure sensor

Engine coolant temp. sensor
P0172
When air±fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on LEAN side
(2 trip detection logic)

Gas leakage on exhaust system

Fuel line pressure

Injector leak, blockage

Heated oxygen sensor (bank 1 sensor 1)

Manifold absolute pressure sensor

Engine coolant temp. sensor
HINT:

When the DTC P0171 is recorded, the actual air±fuel ratio is on the LEAN side. When DTC P0172 is
recorded, the actual air±fuel ratio is on the RICH side.

If the vehicle runs out of fuel, the air±fuel ratio is LEAN and DTC P0171 is recorded. The MIL then
comes on.

If the total of the short±term fuel trim value and long±term fuel trim value is within + 38 %, the system
is functioning normally.

The heated oxygen sensor (bank 1 sensor 1) output voltage and the short±term fuel trim value can
be read using the OBD II scan tool or TOYOTA hand±held tester.
DI4NG±01