2007 TOYOTA SIENNA relay

ES–802GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
P2198 Oxygen (A/F) Sensor
Signal Stuck Rich
(Bank 2 Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor (bank
1, 2 sensor 1) heater
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. Intake system
7. Fuel pressure
8. Injector
9. ECMComes on DTC storedES-355
P2238 Oxygen (A/F) Sensor
Pumping Current
Circuit Low (Bank 1
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
(bank 1, 2 sensor 1)
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372
P2239 Oxygen (A/F) Sensor
Pumping Current
Circuit High (Bank 1
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372
P2241 Oxygen (A/F) Sensor
Pumping Current
Circuit Low (Bank 2
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
(bank 1, 2 sensor 1)
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372
P2242 Oxygen (A/F) Sensor
Pumping Current
Circuit High (Bank 2
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372 DTC Code Detection Item Suspected Trouble
AreaMIL Memory See page

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–81
ES
P2252 Oxygen (A/F) Sensor
Reference Ground
Circuit Low (Bank 1
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372
P2253 Oxygen (A/F) Sensor
Reference Ground
Circuit High (Bank 1
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372
P2255 Oxygen (A/F) Sensor
Reference Ground
Circuit Low (Bank 2
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372
P2256 Oxygen (A/F) Sensor
Reference Ground
Circuit High (Bank 2
Sensor 1)1. Open or short in A/
F sensor (bank 1, 2
sensor 1) circuit
2. A/F sensor (bank
1, 2 sensor 1)
3. A/F sensor heater
4. A/F sensor heater
relay
5. A/F sensor heater
and relay circuits
6. ECMComes on DTC storedES-372
P2401 Evaporative Emission
System Leak
Detection Pump
Control Circuit Low1. Pump module
2. Connector/wire
harness (Pump
module - ECM)
3. ECMComes on DTC storedES-257
P2402 Evaporative Emission
System Leak
Detection Pump
Control Circuit High1. Pump module
2. Connector/wire
harness (Pump
module - ECM)
3. ECMComes on DTC storedES-257
P2419 Evaporative Emission
System Switching
Valve Control Circuit
Low1. Pump module
2. Connector/wire
harness (Pump
module - ECM)
3. ECMComes on DTC storedES-257 DTC Code Detection Item Suspected Trouble
AreaMIL Memory See page

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–109
ES
HINT:
• Although the DTC titles say the 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
Refer to DTC P2195 (See page ES-355).
HINT:
• When any of these DTCs are set, the ECM enters fail-safe mode. The ECM turns off the A/F sensor
heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned off.
• The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The
A/F sensor heater circuit uses a relay on the +B side of the circuit.
DTC P0031Oxygen (A/F) Sensor Heater Control Circuit
Low (Bank 1 Sensor 1)
DTC P0032Oxygen (A/F) Sensor Heater Control Circuit
High (Bank 1 Sensor 1)
DTC P0051Oxygen (A/F) Sensor Heater Control Circuit
Low (Bank 2 Sensor 1)
DTC P0052Oxygen (A/F) Sensor Heater Control Circuit
High (Bank 2 Sensor 1)
DTC No. DTC Detection Condition Trouble Area
P0031
P0051Air-Fuel Ratio (A/F) sensor heater current less than 0.8
A (1 trip detection logic)• Open in A/F sensor heater circuit
• A/F sensor heater
• A/F sensor heater relay
•ECM
A165205E01

ES–1102GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
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 closest sensor to the engine assembly.
• Sensor 2 refers to the furthest sensor away from the engine assembly.
MONITOR DESCRIPTION
The ECM uses information from the Air-Fuel Ratio (A/F) sensor to regulate the air-fuel ratio and keep it
close to the stoichiometric level. This maximizes the ability of the Three-Way Catalytic Converter (TWC) to
purify the exhaust gas.
The A/F sensor detects oxygen levels in the exhaust gas and transmits the information to the ECM. The
inner surface of the sensor element is exposed to the outside air. The outer surface of the sensor element
is exposed to the exhaust gas. The sensor element is made of platinum coated zirconia and includes an
integrated heating element.
The zirconia element generates small voltage when there is a large difference in the oxygen
concentrations between the exhaust gas and outside air. The platinum coating amplifies this voltage
generation.
The A/F sensor is more efficient when heated. When the exhaust gas temperature is low, the sensor
cannot generate useful voltage signals without supplementary heating. The ECM regulates the
supplementary heating using a duty-cycle approach to adjust the average current in the sensor heater
element. If the heater current is outside the normal range, the signal transmitted by the A/F sensor will be
inaccurate, as a result, the ECM will be unable to regulate air-fuel ratio properly.
When the current in the A/F sensor heater is outside the normal operating range, the ECM interprets this
as a malfunction in the sensor heater and sets a DTC.
Example:
The ECM sets DTC P0032 or P0052 when the current in the A/F sensor heater is more than 10 A.
Conversely, when the heater current is less than 0.8 A, DTC P0031 or P0051 is set.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
P0031 and P0051:
P0032
P0052Air-Fuel Ratio (A/F) sensor heater current more than 10
A (1 trip detection logic)• Short in A/F sensor heater circuit
• A/F sensor heater
• A/F sensor heater relay
•ECM
Related DTCsP0031: A/F sensor heater (Bank 1) range check (Low current)
P0032: A/F sensor heater (Bank 1) range check (High current)
P0051: A/F sensor heater (Bank 2) range check (Low current)
P0052: A/F sensor heater (Bank 2) range check (High current)
Required sensors / components (Main) A/F sensor heater
Required sensors / components (Related) -
Frequency of operation Continuous
Duration 10 seconds
MIL operation Immediate
Sequence operation None
The monitor will run whenever these DTCs are not
presentNone
Battery voltage 10.5 V or more
Heater ON duty ratio 50% or moreDTC No. DTC Detection Condition Trouble Area

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–113
ES
(a) Remove the A/F fuse from the engine room junction
block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Below 1
(c) Reinstall the A/F fuse.
NG
OK
(a) Remove the A/F relay from the No. 6 engine room relay
block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
(c) Reinstall the A/F relay.
NG
OK
3INSPECT FUSE (A/F FUSE)
A162360E07
INSPECT FUSE (A/F FUSE)
4INSPECT RELAY (A/F RELAY)
B016200
Tester Connection Specified Condition
3 - 5 10 k
or higher
3 - 5Below 1
(Apply battery voltage between terminals 1 and 2)
REPLACE RELAY (A/F RELAY)

ES–1142GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(a) Disconnect the A5 or A6 A/F sensor connector.
(b) Remove the A/F relay from the No. 6 engine room relay
block.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Check for open
Check for short
(d) Reinstall the A/F relay.
(e) Reconnect the A/F sensor connector.
NG
OK
(a) Remove the A/F relay from the No. 6 engine room relay
block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Check for open
NG
5CHECK HARNESS AND CONNECTOR (A/F SENSOR - A/F RELAY)
A165502E01
Tester Connection Specified Condition
A/F relay terminal (3) - +B (A5-2) Below 1
A/F relay terminal (3) - +B (A6-2) Below 1
Tester Connection Specified Condition
A/F relay terminal (3) - +B (A5-2) - Body ground 10 k
or higher
A/F relay terminal (3) - +B (A6-2) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F SENSOR - A/F RELAY)
6CHECK HARNESS AND CONNECTOR (A/F RELAY - BODY GROUND)
A165503E02
Tester Connection Specified Condition
A/F relay terminal (2) - Body ground Below 1
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F RELAY - BODY GROUND)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–115
ES
OK
(a) Disconnect the A5 or A6 A/F sensor connector.
(b) Disconnect the E10 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 ECM connector.
(e) Reconnect the A/F sensor connectors.
NG
OK
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the intelligent tester ON.
(d) Clear the DTCs (See page ES-39).
(e) Start the engine.
(f) Allow the engine to idle for 1 minute or more.
(g) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DTC INFO / CURRENT CODES.
(h) Read the DTCs.
Result
B REPAIR OR REPLACE HARNESS OR CONNECTOR (A/F RELAY - BATTERY)
7CHECK HARNESS AND CONNECTOR (A/F RELAY - ECM)
A085836E04
Tester Connection Specified Condition
HT (A5-1) - HA1A (E10-2) Below 1
HT (A6-1) - HA2A (E10-1) Below 1
Tester Connection Specified Condition
HT (A5-1) or HA1A (E10-2) - Body ground 10 k
or higher
HT (A6-1) or HA2A (E10-1) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F RELAY - ECM)
8CHECK WHETHER DTC OUTPUT RECURS
Display (DTC Output) Proceed to
No output A
P0031, P0032, P0051 and/or P0052 B
REPLACE ECM (See page ES-498)

ES–1182GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
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 closest to the engine assembly.
• Sensor 2 refers to the sensor furthest away from the engine assembly.
MONITOR DESCRIPTION
The sensing position of the Heated Oxygen (HO2) sensor has a zirconia element which is used to detect
the oxygen concentration in the exhaust gas. If the zirconia element is at the appropriate temperature,
and the difference between the oxygen concentrations surrounding the inside and outside surfaces of the
sensor is large, the zirconia element generates voltage signals. In order to increase the oxygen
concentration detecting capacity of the zirconia element, the ECM supplements the heat from the exhaust
with heat from a heating element inside the sensor.
Heated oxygen sensor heater range check (P0037, P0038, P0057 and P0058):
The ECM monitors the current applied to the O2 sensor heater to check the heater for malfunctions. If the
current is below the threshold value, the ECM will determine that there is an open circuit in the heater. If
the current is above the threshold value, the ECM will determine that there is a short circuit in the heater.
Example:
The ECM sets DTC P0038 or P0058 when the current in the HO2 sensor heater is more than 2 A.
Conversely, when the heater current is less than 0.3 A, DTC P0037 or P0057 is set.
Heated oxygen sensor heater performance (P0141 and P0161):
After the accumulated heater ON time exceeds 100 seconds, the ECM calculates the heater resistance
using the battery voltage and the current applied to the heater. If the resistance is above the threshold
value, the ECM will determine that there is a malfunction in the HO2S heater and set DTC P0141 and
P0161.
MONITOR STRATEGY
DTC No. DTC Detection Condition Trouble Area
P0037
P0057Heated Oxygen (HO2) sensor heater current is less
than 0.3 A (1 trip detection logic)• Open in HO2 sensor heater circuit
• HO2 sensor heater
• EFI relay
•ECM
P0038
P0058Heated Oxygen (HO2) sensor heater current is more
than 2 A (1 trip detection logic)• Open in HO2 sensor heater circuit
• HO2 sensor heater
• EFI relay
•ECM
P0141
P0161Cumulative heater resistance correction value exceeds
the acceptable threshold (2 trip detection logic)• HO2 sensor
•ECM
Related DTCsP0037: Heated oxygen sensor heater (bank 1) open/short (Low electrical current)
P0038: Heated oxygen sensor heater (bank 1) open/short (High electrical current)
P0057: Heated oxygen sensor heater (bank 2) open/short (Low electrical current)
P0058: Heated oxygen sensor heater (bank 2) open/short (High electrical current)
P0141: Heated oxygen sensor heater performance (bank 1 sensor 2)
P0161: Heated oxygen sensor heater performance (bank 2 sensor 2)
Required Sensors / Components (Main) Heated oxygen sensor heater (bank 1 and 2)
Required Sensors / Components (Related) Vehicle speed sensor
Frequency of Operation Continuous
Duration0.5 seconds: P0037 and P0057
1 second: P0038 and P0058
10 seconds: P0141 and P0161
MIL OperationImmediate: P0037, P0038, P0057 and P0058
2 driving cycles: P0141 and P0161
Sequence of Operation None