TOYOTA SIENNA 2007 Service Repair Manual

ES–3582GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
B
ASYSTEM OK
REPLACE ECM (See page ES-498)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–359
ES
HINT:
This DTC relates to the Accelerator Pedal Position (APP) sensor.
DESCRIPTION
Refer to DTC P2120 (See page ES-343).
MONITOR DESCRIPTION
The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal
position sensor has 2 sensor elements and 2 signal outputs: VPA and VPA2. VPA is used to detect the
actual accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA.
When the difference between the voltage outputs of VPA and VPA2 deviates from the standard, the ECM
determines that the accelerator pedal position sensor is malfunctioning. The ECM turns on the MIL and
the DTC is set.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
FAIL-SAFE
The accelerator pedal position sensor has 2 (main and sub) sensor circuits. If a malfunction occurs in
either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the 2 sensor
circuits and switches to limp mode. In limp mode, the functioning circuit is used to calculate the
accelerator pedal opening angle to allow the vehicle to continue driving. If both circuits malfunction, the
ECM regards the opening angle of the accelerator pedal as being fully closed. In this case, the throttle
valve remains closed as if the engine is idling.
DTC P2121Throttle / Pedal Position Sensor / Switch "D"
Circuit Range / Performance
DTC No. DTC Detection Condition Trouble Area
P2121Difference between VPA and VPA2 is less than 0.4 V, or
more than 1.2 V for 0.5 seconds (1 trip detection logic)• Accelerator position (APP) sensor
•ECM
Related DTCs P2121: Accelerator pedal position (APP) sensor rationality
Required Sensors / Components (Main) APP sensor
Required Sensors / Components (Related) -
Frequency of Operation Continuous
Duration 0.5 seconds
MIL Operation Immediate
Sequence of Operation None
The monitor will run whenever these DTCs are not
presentNone
Either of the following conditions is met. Condition 1 or 2
1. Ignition switch ON
2. Electronic throttle actuator power ON
Difference between VPA1 voltage (learned value) and
VPA2 voltage (learned value)Less than 0.4 V, or more than 1.2 V

ES–3602GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
If a pass condition is detected and then the ignition switch is turned off, the fail-safe operation stops and
the system returns to a normal condition.
WIRING DIAGRAM
Refer to DTC P2120 (See page ES-347).
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition
information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data
can be helpful in determining whether the vehicle was running or stopped, whether the engine was
warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of
a malfunction.
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the
tester on.
(c) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DATA LIST / ALL / ACCEL POS #1
and ACCEL POS #2.
(d) Read the values displayed on the tester.
Standard voltage
OK
NG
1READ VALUE OF INTELLIGENT TESTER (ACCEL POS #1 AND ACCEL POS #2)
FI07052E14Accelerator Pedal
OperationACCEL POS #1 (AP#1) ACCEL POS #2 (AP#2)
Released 0.5 to 1.1 V 1.2 to 2.0 V
Depressed 2.6 to 4.5 V 3.4 to 5.0 V
Go to step 4

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–361
ES
(a) Disconnect the A15 Accelerator Pedal Position (APP)
sensor connector.
(b) Disconnect the E4 ECM connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance :
Check for open
Check for short
(d) Reconnect the APP sensor connector.
(e) Reconnect the ECM connector.
NG
OK
(a) Replace the accelerator pedal rod assembly (See page
ES-502).
NEXT
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the
tester on.
(c) Clear the DTCs (See page ES-39).
(d) Start the engine.
(e) Allow the engine to idle for 15 seconds.
2CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR -
ECM)
A114633E09
Tester Connection Specified Condition
VPA1 (A15-6) - VPA (E4-18) Below 1
EP1 (A15-5) - EPA (E4-20) Below 1
VCP1 (A15-4) - VCPA (E4-26) Below 1
VPA2 (A15-3) - VPA2 (E4-19) Below 1
EP2 (A15-2) - EPA2 (E4-21) Below 1
VCP2 (A15-1) - VCP2 (E4-27) Below 1
Tester Connection Specified Condition
VPA1 (A15-6) or VPA (E4-18) - Body ground 10 k
or higher
EP1 (A15-5) or EPA (E4-20) - Body ground 10 k
or higher
VCP1 (A15-4) or VCPA (E4-26) - Body ground 10 k
or higher
VPA2 (A15-3) or VPA2 (E4-19) - Body ground 10 k
or higher
EP2 (A15-2) or EPA2 (E4-21) - Body ground 10 k
or higher
VCP2 (A15-1) or VCP2 (E4-27) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (ACCELERATOR PEDAL
POSITION SENSOR - ECM)
3REPLACE ACCELERATOR PEDAL ROD
4CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR
DTCS)

ES–3622GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(f) Select the following menu items on the tester:
DIAGNOSIS / ENHANCED OBD II / DTC INFO /
CURRENT CODES.
(g) Read the DTCs.
Result
B
A
Display (DTC Output) Proceed to
P2121 A
No output B
SYSTEM OK
REPLACE ECM (See page ES-498)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–363
ES
HINT:
• Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
• Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and
located near the engine assembly.
DESCRIPTION
The A/F sensor generates a voltage* that corresponds to the actual air-fuel ratio. This sensor voltage is
used to provide the ECM with feedback so that it can control the air-fuel ratio. The ECM determines the
deviation from the stoichiometric air-fuel ratio level, and regulates the fuel injection time. If the A/F sensor
malfunctions, the ECM is unable to control the air-fuel ratio accurately.
The A/F sensor is the planar type and is integrated with the heater, which heats the solid electrolyte
(zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust
gas temperature is low), a current flows into the heater to heat the sensor, in order to facilitate accurate
oxygen concentration detection. In addition, the sensor and heater portions are narrower than the
conventional type. The heat generated by the heater is conducted to the solid electrolyte through the
alumina, therefore the sensor activation is accelerated.
A three-way catalytic converter (TWC) is used in order to convert the carbon monoxide (CO), hydro
carbon (HC), and nitrogen oxides (HOx) into less harmful substances. To allow the TWC to function
effectively, it is necessary to keep the air-fuel ratio of the engine near the stoichiometric air-fuel ratio.
*: Value changes inside the ECM. Since the A/F sensor is the current output element, a current is
converted to a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors
will show a constant voltage.
DTC P2195Oxyg en ( A/ F) S en so r S ig n al Stu ck Lea n (Ban k 1
Sensor 1)
DTC P2196Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1
Sensor 1)
DTC P2197Oxyg en ( A/ F) S en so r S ig n al Stu ck Lea n (Ban k 2
Sensor 1)
DTC P2198Oxygen (A/F) Sensor Signal Stuck Rich (Bank 2
Sensor 1)
G038016E06

ES–3642GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
HINT:
• DTCs P2195 and P2196 indicate malfunctions related to the bank 1 A/F sensor circuit.
• DTCs P2197 and P2198 indicate malfunctions related to the bank 2 A/F sensor circuit.
• Bank 1 refers to the bank that includes cylinder No. 1.
• Bank 2 refers to the bank that includes cylinder No. 2.
• When any of these DTCs are set, check the A/F sensor voltage output by selecting the following menu
items on the intelligent tester: DIAGNOSIS / ENHANCED OBDII / DATA LIST / PRIMARY / AFS B1S1.
• Short-term fuel trim values can also be read using the intelligent tester.
• The ECM regulates the voltages at the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a
constant level. Therefore, the A/F sensor voltage output cannot be confirmed without using the
intelligent tester.
• If an A/F sensor malfunction is detected, the ECM sets a DTC.
MONITOR DESCRIPTION
Sensor voltage detection monitor
Under the air-fuel ratio feedback control, if the A/F sensor voltage output indicates rich or lean for a certain
period of time, the ECM determines that there is a malfunction in the A/F sensor. The ECM illuminates the
MIL and sets a DTC.
Example:
If the A/F sensor voltage output is less than 2.8 V (very rich condition) for 10 seconds, despite the HO2
sensor voltage output being less than 0.6 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor
voltage output is more than 3.8 V (very lean condition) for 10 seconds, despite the HO2 sensor voltage
output being 0.15 V or more, DTC P2195 is set.
Sensor current detection monitor
A rich air-fuel mixture causes a low A/F sensor current, and a lean air-fuel mixture causes a high A/F
sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high
during deceleration with the throttle valve fully closed. The ECM monitors the A/F sensor current during
fuel-cut and detects any abnormal current values.
If the A/F sensor output is 3.6 mA or more for more than 3 seconds of cumulative time, the ECM interprets
this as a malfunction in the A/F sensor and sets DTC P2195 (high-side stuck). If the A/F sensor output is
1.0 mA or less for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck).
DTC No. DTC Detection Condition Trouble Area
P2195
P2197Conditions (a) and (b) continue for 2 seconds or more
(2 trip detection logic):
(a) Air-Fuel Ratio (A/F) sensor voltage is more than 3.8
V
(b) Heated Oxygen (HO2) sensor voltage is 0.15 V or
more• Open or short in A/F sensor (bank 1, 2 sensor 1)
circuit
• A/F sensor (bank 1, 2 sensor 1)
• A/F sensor (bank 1, 2 sensor 1) heater
• A/F sensor heater relay
• A/F sensor heater and relay circuits
• Intake system
• Fuel pressure
• Injector
•ECM
P2195
P2197While fuel-cut operation is performed (during vehicle
deceleration), air-furl ratio (A/F) sensor current is 3.6
mA or more for 3 seconds (2 trip detection logic)• A/F sensor
•ECM
P2196
P2198Conditions (a) and (b) continue for 2 seconds or more
(2 trip detection logic):
(a) A/F sensor voltage is less than 2.8 V
(b) HO2 sensor voltage is less than 0.6 V• Open or short in A/F sensor (bank 1, 2 sensor 1)
circuit
• A/F sensor (bank 1, 2 sensor 1)
• A/F sensor (bank 1, 2 sensor 1) heater
• A/F sensor heater relay
• A/F sensor heater and relay circuits
• Intake system
• Fuel pressure
•Injector
•ECM
P2196
P2198While fuel-cut operation is performed (during vehicle
deceleration), air-furl ratio (A/F) sensor current is less
than 1.4 mA for 3 seconds (2 trip detection logic)• A/F sensor
•ECM

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–365
ES
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
Sensor voltage detection monitor (Lean side malfunction P2195, P2197):
Related DTCsP2195: A/F sensor (Bank 1) signal stuck lean
P2196: A/F sensor (Bank 1) signal stuck rich
P2197: A/F sensor (Bank 2) signal stuck lean
P2198: A/F sensor (Bank 2) signal stuck rich
Required Sensors / Components (Main) A/F sensor
Required Sensors / Components (Related) HO2 sensor
Frequency of Operation Continuous
DurationSensor voltage detection monitor: 10 seconds
Sensor current detection monitor: 3 seconds
MIL Operation 2 driving cycles
Sequence of Operation None
The monitor will run whenever these DTCs are not
presentP0031, P0032, P0051, P0052 (A/F Sensor heater Sensor 1), P0037, P0038, P0057
P0058 (O2 Sensor heater Sensor 2), P0100, P0101, P0102, P0103 (MAF Sensor),
P0110, P0112, P0113 (IAT Sensor), P0115, P0116, P0117, P0118 (ECT Sensor),
P0120, P0121, P0122, P0220, P0222, P0223 (TP Sensor), P0125 (Insufficient ECT
for Closed Loop), P0136, P0156 (O2 Sensor 2), P0171, P0172 (Fuel System),
P0300, P0301, P0302, P0303, P0304, P0305, P0306 (Misfire), P0335 (CKP
Sensor), P0340 (CMP Sensor), P0450, P0451, P0452, P0453, P0455, P0456 (EVAP
System), P0500 (VSS)
Duration while all of the following conditions are met 2 seconds or more
Rear HO2 sensor voltage 0.15 V or more
Time after engine start 30 seconds or more
A/F sensor status Activated
Fuel system status Closed-loop
Engine Running
G034989E05

ES–3662GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
Sensor voltage detection monitor (Rich side malfunction P2196, P2198):
Sensor Current detection monitor P2195, P2196, P2197, P2198
TYPICAL MALFUNCTION THRESHOLDS
Sensor voltage detection monitor (Lean side malfunction P2195, P2197):
Sensor voltage detection monitor (Rich side malfunction P2196, P2198):
Sensor current detection monitor (High side malfunction P2195, P2197):
Sensor current detection monitor (Rich side malfunction P2196, P2198):
MONITOR RESULT
Refer to CHECKING MONITOR STATUS (See page ES-19).
Duration while all of the following conditions are met 2 seconds or more
Rear HO2 sensor voltage Less than 0.6 V
Time after engine start 30 seconds or more
A/F sensor status Activated
Fuel system status Closed-loop
Engine Running
Battery voltage 11 V or more
Atmospheric pressure 0.75 or more
Air-fuel ratio sensor status Activated
Engine coolant temperature 75
C (167F) or more
Continuous time of fuel-cut 3 to 10 seconds
A/F sensor voltage More than 3.8 V
A/F sensor voltage Less than 2.8 V
Air-fuel ratio sensor current during fuel cut 3.6 mA or more
Air-fuel ratio sensor current during fuel cut Less than 1.4 mA

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–367
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WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
This confirmation driving pattern is used in steps 4, 7, 17, and 21 of the following diagnostic
troubleshooting procedure when using the intelligent tester.
A165206E01