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EC-544Revision: June 2006
DTC P2A00 A/F SENSOR 1
2007 Versa
2. RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1
Loosen and retighten the air fuel ratio (A/F) sensor 1 (2).
Air fuel ratio (A/F) sensor harness connector (1)
>> GO TO 3.
3. CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0699E
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DTC P2A00 A/F SENSOR 1
EC-545
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4. CLEAR THE SELF-LEARNING DATA.
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 and P0172 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor (1) harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-60, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 and P0172 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171 or P0172. Refer to EC-276, "DTC P0171 FUEL INJEC-
TION SYSTEM FUNCTION" or EC-284, "DTC P0172 FUEL INJECTION SYSTEM FUNCTION" .
No >> GO TO 5.
5. CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector (1).
–Air fuel ratio (A/F) sensor (2)
3. Check harness connector for water.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness connector.
PBIB2035E
BBIA0701E
Water should no exist.
BBIA0699E
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EC-546Revision: June 2006
DTC P2A00 A/F SENSOR 1
2007 Versa
6. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between A/F sensor 1 terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E8, F8
Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
8. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals. Refer to Wiring Diagram.
4. Check harness continuity between ECM terminals 49, 53 or A/F sensor 1 terminals 1, 2 and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK A/F SENSOR 1 HEATER
Refer to EC-165, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10. CHECK INTERMITTENT INCIDENT
Perform EC-143, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.Voltage: Battery voltage
PBIB3308E
A/F sensor 1 terminal ECM terminal
149
253
Continuity should exist.
Continuity should not exist.
Page 1716 of 2896
DTC P2A00 A/F SENSOR 1
EC-547
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11 . REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads using Heated Oxy-
gen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>> GO TO 12.
12. CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch ON.
2. Select “A/F ADJ-B1” in “DATA MONITOR” mode with CON-
SULT-II.
3. Make sure that “0.000” is displayed on CONSULT-II screen.
OK or NG
OK >>INSPECTION END
NG >> GO TO 13.
PBIB3201E
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EC-548Revision: June 2006
DTC P2A00 A/F SENSOR 1
2007 Versa
13. CLEAR A/F ADJUSTMENT DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness (1) connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-60, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
>> GO TO 14.
14. CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select “A/F ADJ-B1” in “DATA MONITOR” mode with CON-
SULT-II.
3. Make sure that “0.000” is displayed on CONSULT-II screen.
>>INSPECTION END
Removal and InstallationUBS00QNV
AIR FUEL RATIO SENSOR
Refer to EM-21, "EXHAUST MANIFOLD" .
PBIB2035E
BBIA0701E
PBIB3201E
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ASCD BRAKE SWITCH
EC-549
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ASCD BRAKE SWITCHPFP:25320
Component DescriptionUBS00QNW
When depress on the brake pedal, ASCD brake switch (2) is turned
OFF and stop lamp switch (1) is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal)
Refer to EC-28, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)"
for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00QNX
Specification data are reference values.
BBIA0708E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch)
Ignition switch: ON
Brake pedal: Fully released (A/T, CVT)
Brake pedal and clutch pedal: Fully
released (M/T)ON
Brake pedal: Slightly depressed (A/T, CVT)
Brake pedal and/or clutch pedal: Slightly
depressed (M/T)OFF
BRAKE SW2
(Stop lamp switch)
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
Page 1719 of 2896
EC-550Revision: June 2006
ASCD BRAKE SWITCH
2007 Versa
Wiring DiagramUBS00QNY
BBWA2666E
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ASCD BRAKE SWITCH
EC-551
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Revision: June 20062007 Versa
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
99 R Stop lamp switch[Ignition switch: ON]
Brake pedal: Fully releasedApproximately 0V
[Ignition switch: ON]
Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
100 G ASCD brake switch[Ignition switch: ON]
Brake pedal: Slightly depressed (A/T, CVT)
Brake pedal and/or clutch pedal: Slightly
depressed (M/T) Approximately 0V
[Ignition switch: ON]
Brake pedal: Fully released (A/T, CVT)
Brake pedal and clutch pedal: Fully released
(M/T)BATTERY VOLTAGE
(11 - 14V)