heater TOYOTA CAMRY 1999 Service Manual PDF

A02509
HAFL (+)
HAFR (+)
± DIAGNOSTICSENGINE (1MZ±FE)
DI±349
584 Author: Date:
DTC P1135 A/F Sensor Heater Circuit Malfunction
(Bank 1 Sensor 1) (Only for California Spec.)
DTC P1155 A/F Sensor Heater Circuit Malfunction
(Bank 2 Sensor 1) (Only for California Spec.)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Only for California Spec.))
on page DI±249.
DTC No.DTC Detecting ConditionTrouble Area
P1135
When heater operates, heater current exceeds 8 A
(2 trip detection logic)
Open or in heater circuit of A/F sensors
(bank 1, 2 sensor 1)P1135
P1155Heater current of 0.25 A or less when heater operates
(2 trip detection logic)
(bank 1, 2 sensor 1)

A/F sensors (bank 1, 2 sensor 1) heater

ECM
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Only for California Spec.))
on page DI±249.
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 voltage between terminal HAFR, HAFL of ECM connector and body
ground.
PREPARATION:
(a) Remove glove compartment (See page SF±73).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals HAFR, HAFL of the ECM
connector and body ground.
OK:
Voltage: 9 ~ 14 V
OK Check and replace ECM (See page IN±31).
NG
DI1K8±04

DI±350
± DIAGNOSTICSENGINE (1MZ±FE)
585 Author: Date:
2 Check resistance of A/F sensor heaters (bank 1, 2 sensor 1) (See page SF±68).
NG Replace A/F sensors (bank 1, 2 sensor 1).
OK
Check and repair harness or connector between EFI main relay (Marking: EFI) and A/F sensors
(bank 1, 2 sensor 1), and A/F sensors (bank 1, 2 sensor 1) and ECM (See page IN±31).

AB0119H01298H01299
Airbag Sensor Assembly
ON
ACC
IG2
(+) (±)
H01249
ON
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±789
1024 Author: Date:
2 Check source voltage.
PREPARATION:
Connect negative (±) terminal cable to the battery.
CHECK:
(a) Turn ignition switch ON.
(b) Measure the voltage each of IG2 and ACC on the sensor
and operate electric system. (defogger, wiper, headlight,
heater blower, etc.)
OK:
Voltage: 10 ± 14 V
NG Check harness between battery and airbag sen-
sor assembly, and check battery and charging
system.
OK
3 Does SRS warning light turn off?
PREPARATION:
(a) Turn ignition switch to LOCK.
(b) Connect the steering wheel pad connector.
(c) Connect the front passenger airbag assembly connector.
(d) Connect the airbag sensor assembly connectors.
(e) Connect the side airbag assembly connectors.
(f) Connect the seat belt pretensioner connectors.
(g) Connect the side airbag sensor assembly connectors.
(h) Connect the front airbag sensor connectors.
(i) Turn ignition switch to ON.
CHECK:
Operate electric system (defogger, wiper, headlight, heater
blower, etc.) and check that SRS warning light goes off.
NO Check for DTCs. If a DTC is output, perform trou-
bleshooting for the DTC. If a normal code is out-
put, replace airbag sensor assembly.
YES
From the results of the above inspection, the malfunctioning part can now be considered normal.
To make sure of this, use the simulation method to check.

FI3605
ON
OFFFlashing
0.13 Second
± DIAGNOSTICSENGINE
DI±7
(3) Prepare the TOYOTA hand±held tester.
(4) Connect the TOYOTA hand±held tester to the
DLC3 under the instrument panel lower pad.
(5) Turn the ignition switch ON and push the TOYOTA
hand±held tester ON.
(6) Switch the TOYOTA hand±held tester from the nor-
mal mode to the check mode. (Check that the MIL
flashes.)
NOTICE:
If the TOYOTA hand±held tester switches the ECM from
normal mode to check mode or vice±versa, or if the igni-
tion switch is turned from ON to ACC or LOCK during check
mode, the DTCs and freezed frame data will be erased.
(7) Start the engine. (The MIL goes out after the engine
start.)
(8) Simulate the conditions of the malfunction de-
scribed by the customer.
NOTICE:
Leave the ignition switch ON until you have checked the
DTC, etc.
(9) After simulating the malfunction conditions, use the
TOYOTA hand±held tester diagnosis selector to
check the DTCs and freezed frame data, etc.
HINT:
Take care not to turn the ignition switch OFF. Turning the ignition
switch OFF switches the diagnosis system from check mode to
normal mode. So all DTCs, etc. are erased.
(10) After checking the DTC, inspect the applicable cir-
cuit.
4. FAIL±SAFE CHART
If any of the following codes is recorded, the ECM enters fail±safe mode.
DTC No.Fail±Safe OperationFail±Safe Deactivation Conditions
P0105Ignition timing fixed at 5° BTDCReturned to normal condition
P0110Intake air temperature is fixed at 20°C (68°F)Returned to normal condition
P0115Engine coolant temperature is fixed at 80°(176°F)Returned to normal condition
P0120VTA is fixed at 0°The following condition must be repeated at least 2 times con-
secutively VTA 0.1 V and  0.95 V
P0141The heater circuit in witch an abnormality is detected is
turned offIgnition switch OFF
P1135The heater circuit in which an abnormality is detected is
turned offIgnition switch OFF
P1300
P1310Fuel cutIGF signal is detected for 2 consecutive ignitions

DI00I±11
DI±14
± DIAGNOSTICSENGINE
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for that code listed
in the table below. For details of each code, turn to the page referred to under the ''See page '' for the respec-
tive ''DTC No.'' in the DTC chart.
1. SAE CONTROLLED
DTC No.
(See page)Detection ItemTrouble AreaMIL*Memory
P0105
(DI±22)Manifold Absolute Pressure/
Barometric Pressure Circuit Mal-
function
Open or short in manifold absolute pressure sensor circuit

Manifold absolute pressure sensor

ECM

P0106
(DI±25)Manifold Absolute Pressure Cir-
cuit Range/Performance Prob-
lem
Vacuum line

Manifold absolute pressure sensor
P0110
(DI±26)Intake Air Temp. Circuit Malfunc-
tion
Open or short in intake air temp. sensor circuit

Intake air temp. sensor

ECM

P0115
(DI±30)Engine Coolant Temp. Circuit
Malfunction
Open or short in engine coolant temp. sensor circuit

Engine coolant temp. sensor

ECM

P0116
(DI±34)Engine Coolant Temp. Circuit
Range/Performance Problem
Cooling system

Engine coolant temp. sensor
P0120
(DI±35)Throttle/Pedal Position Sensor/
Switch ºAº Circuit Malfunction
Open or short in throttle position sensor circuit

Throttle position sensor

ECM

P0121
(DI±39)Throttle/Pedal Position Sensor/
Switch ºAº Circuit Range/Perfor-
mance Problem

Throttle position sensor
P0125
(DI±40)Insufficient Coolant Temp. for
Closed Loop Fuel Control

Open or short in A/F sensor (bank 1 sensor 1) circuit

A/F sensor (bank 1 sensor 1)

Air induction system

EGR system

Fuel pressure

Injector

Gas leakage on exhaust system

ECM

P0136
(DI±45)Oxygen Sensor Circuit Malfunc-
tion (Bank 1 Sensor 2)
Open or short in heated oxygen sensor circuit

Heated oxygen sensor
P0141
(DI±47)Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 2)
Open or short in heater circuit of heated oxygen sensor

Heated oxygen sensor heater

ECM

P0171
(DI±49)System too Lean (Fuel Trim)

Air induction system

Injector blockage

Manifold absolute pressure sensor

Engine coolant temp. sensor

Fuel shutoff valve for delivery pipe

Gas leakage on exhaust system

Open or short in A/F sensor (bank 1 sensor 1) circuit

A/F sensor (bank 1 sensor 1)

ECM


± DIAGNOSTICSENGINE
DI±15
P0172
(DI±49)System too Rich (Fuel Trim)

Injector leak, blockage

Manifold absolute pressure sensor

Engine coolant temp. sensor

Ignition system

Fuel shutoff valve for delivery pipe

Gas leakage on exhaust system

Open or short in A/F sensor (bank 1 sensor 1) circuit

A/F sensor (bank 1 sensor 1)

ECM

P0180
(DI±54)Fuel Temperature Sensor ºAº
Circuit Malfunction

Open or short in fuel temperature sensor circuit for delivery
pipe

Fuel temperature sensor for delivery pipe

ECM

P0190
(DI±56)Fuel Rail Pressure Sensor Cir-
cuit Malfunction
Open or short in fuel pressure sensor circuit for delivery pipe

Fuel pressure sensor for delivery pipe

ECM

P0335
(DI±59)Crankshaft Position Sensor ºAº
Circuit Malfunction

Open or short in crankshaft position sensor circuit

Crankshaft position sensor

Crankshaft timing pulley

ECM

P0340
(DI±61)Camshaft Position Sensor Circuit
Malfunction

Open or short in camshaft position sensor circuit

Camshaft position sensor

Camshaft timing pulley

ECM

P0400
(DI±63)Exhaust Gas Recirculation Flow
Malfunction

Vacuum or EGR hose is connected to wrong post

Open or short in VSV circuit for EGR

VSV for EGR

EGR system

EGR vacuum modulator

EGR valve

Manifold absolute pressure sensor

ECM

P0500
(DI±69)Vehicle Speed Sensor Malfunc-
tion

Combination meter

Open or short in vehicle speed sensor circuit

Vehicle speed sensor

ECM

P0505
(DI±72)Idle Control System Malfunction

Open or short in IAC valve circuit

IAC valve is stuck or closed

Open or short in A/C switch circuit

Air induction system

ECM

*: MIL lights up
2. MANUFACTURER CONTROLLED
DTC No.
(See Page)Detection ItemTrouble AreaMIL*Memory
P1130
(DI±79)A/F Sensor Circuit Range/Perfor-
mance Malfunction (Bank 1 Sen-
sor 1)

Open or short in A/F sensor circuit

A/F sensor

Air induction system

EGR system

Fuel pressure

Injector

ECM

P1135
(DI±84)A/F Sensor Heater Circuit Mal-
function (Bank 1 Sensor 1)
Open or short in heater circuit of A/F sensor

A/F sensor heater

ECM


A00477
Atmosphere
Cover
Exhaust GasPlatinum
Electrode
Solid Electrolyte
(Zirconia Element)
Platinum
Electrode
Heater
Air±Fuel Ratio
(V)
2.6 4.0
3.8
3.6
3.4
3.2
3.0
2.8
2.4
14 15 16 17 19 21 22
Coating (Ceramic)
ECM Monitored
A/F Sensor Voltage
DI±40
± DIAGNOSTICSENGINE
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three±way cata-
lytic converter is used, but for the most efficient use of the three±way catalytic converter, the air±fuel ratio
must be precisely controlled so that it is always close to the stoichiometric air±fuel ratio.
The A/F sensor has the characteristic that provides output voltage
* approximately proportional to the exist-
ing air±fuel ratio. The A/F sensor output voltage
* is used to provide feedback for the ECM to control the air±
fuel ratio.
By the A/F sensor output, the ECM can determine the deviation amount from the stoichiometric air±fuel ratio
and control the proper injection time immediately. If the A/F sensor is malfunctioning, ECM is unable to per-
form accurate air±fuel ratio control.
The A/F sensor is equipped with a heater which heats the zirconia element. The heater is controlled by the
ECM. When the intake air volume is low (the temp. of the exhaust gas is low), current flows to the heater
to heat the sensor for accurate oxygen concentration detection.
*: The voltage value changes at the inside of the ECM only.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After engine is warmed up, A/F sensor output* does not
change when conditions (a), (b) and (c) continue for at least
1.5 min.:
*: Output value changes at inside of ECM only
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 ± 100 km/h (25 ± 62 mph)
(c) Throttle valve is not fully closed
Open or short in A/F sensor (bank 1 sensor 1) circuit

A/F sensor (bank 1 sensor 1)

Air induction system

EGR system

Fuel pressure

Injector

Gas leakage on exhaust system

ECM
HINT:

After confirming DTC P0125, use the OBD II scan tool or TOYOTA hand-held tester to confirm voltage
output of A/F sensor from the CURRENT DATA.

The ECM controls the voltage of the AF+ and AF± terminals of the 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.
DI1JU±04

DI±42
± DIAGNOSTICSENGINE
2 Connect OBD II scan tool or TOYOTA hand±held tester, and read value for volt-
age output of A/F sensor (bank 1 sensor 1).
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3.
(b) Warm up the A/F sensor with the engine speed at 2,500 rpm for approx. 90 sec.
CHECK:
Read the voltage value of the A/F sensor on the screen of OBD II scan tool or TOYOTA hand±held tester
when you perform all the following conditions.
HINT:
The voltage of the AF+ terminal of the ECM is 3.3 V fixed and the A/F± terminal is 3.0 V fixed. Therefore,
it is impossible to check the A/F sensor output voltage at the terminals (AF+/AF±) of the ECM.
OK:
ConditionA/F Sensor Voltage Value
Engine idling
Engine racing
Not remains at 3.30 V (0.660 V*)
Driving at engine speed 1,500 rpm or more and vehicle
speed 40 km/h (25 mph) or more, and operate throttle valve
open and close
Not remains at 3.30 V (0.660 V)

Not remains at 4.5 V (0.76 V*) or more
*: When you use the OBD II scan tool (excluding TOYOTA hand±held tester)
HINT:

During fuel enrichment, there is a case that the output voltage of the A/F sensor is below 2.8 V (0.56
V*), it is normal.

During fuel cut, there is a case that the output voltage of the A/F sensor is above 3.8 V (0.76 V*), it
is normal.

If the output voltage of the A/F sensor remains at 3.30 V (0.660 V*) even after performing all the above
conditions, A/F the sensor circuit may be open.

If the output voltage of the A/F sensor remains at 4.5 V (0.76 V*) or more, even after performing all
the above conditions, A/F sensor circuit may be short.
*: When you use the OBD II scan tool (excluding TOYOTA hand±held tester).
OK Go to step 10.
NG
3 Check for open and short in harness and connector between ECM and A/F sen-
sor (bank 1 sensor 1) (See page IN±29).
NG Repair or replace harness or connector.
OK
4 Check resistance of A/F sensor heater (bank 1 sensor 1) (See Pub. No. RM654U,
page SF±59).

A09296BE6653A09265
ON
HT2
(±) (+)
± DIAGNOSTICSENGINE
DI±47
DTC P0141 Oxygen Sensor Heater Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI±40.
DTC No.DTC Detecting ConditionTrouble Area
P0141When heater operates, heater current exceeds 2 A
(2 trip detection logic)
Open or short in heater circuit of heated oxygen sensor
Htd ht
P0141Heater current of 0.2 A or less when heater operates
(2 trip detection logic)
Heated oxygen sensor heater

ECM
HINT:

Sensor 1 refers to the sensor closer to the engine body.

Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 on page DI±40.
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 was warmed up or not, the air±fuel ratio was lean
or rich, etc. at the time of the malfunction.
1 Check voltage between terminals HT2 of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals HT2 of the ECM con-
nector and body ground.
HINT:
OK:
Voltage: 9 ± 14 V
OK Check and replace ECM (See page IN±29).
NG
DI00X±05

DI±48
± DIAGNOSTICSENGINE
2 Check resistance of heated oxygen sensor heater (See Pub. No. RM654U, page
SF±63).
NG Replace heated oxygen sensor.
OK
Check and repair harness or connector between EFI main relay (Marking: EFI) and heated oxygen
sensor, and heated oxygen sensor and ECM (See page IN±29).