ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-65
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tified codes can be identified by using the CONSULT-III or GST. A DTC will be used as an example for how to
read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes as follows. The length of
time the 1,000th-digit numeral flashes on and off is 1.2 seconds consisting of an ON (0.6-second) - OFF (0.6-
second) cycle. The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second
OFF cycle. A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other
words, the later numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-8, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal.
Refer to EC-64, "
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)" .
If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.
Be careful not to erase the stored memory before starting trouble diagnoses.
OBD System Operation ChartNBS00033
RELATIONSHIP BETWEEN MIL, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS
When a malfunction is detected for the 1st time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.
Number 0123456789ABCDEF
Flashes 10123456789111213141516
PBIB3005E
EC-66
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2006 November2007 350Z
When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MIL will come on. For details, refer to EC-47, "
Two Trip Detection
Logic" .
The MIL will go off after the vehicle is driven 3 times (driving pattern B) with no malfunction. The drive is
counted only when the recorded driving pattern is met (as stored in the ECM). If another malfunction
occurs while counting, the counter will reset.
The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A)
without the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and
Fuel Injection System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times
(driving pattern C) without the same malfunction recurring. The “TIME” in “SELF-DIAGNOSTIC
RESULTS” mode of CONSULT-III will count the number of times the vehicle is driven.
The 1st trip DTC is not displayed when the self-diagnosis results in OK for the 2nd trip.
SUMMARY CHART
For details about patterns B and C under “Fuel Injection System” and “Misfire”, see EC-68 .
For details about patterns A and B under “Other”, see EC-70
.
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.Items Fuel Injection System Misfire Other
MIL (goes off) 3 (pattern B) 3 (pattern B) 3 (pattern B)
DTC, Freeze Frame Data (no
display)80 (pattern C) 80 (pattern C) 40 (pattern A)
1st Trip DTC (clear)
1 (pattern C), *
11 (pattern C), *11 (pattern B)
1st Trip Freeze Frame Data
(clear)*1, *2 *1, *2 1 (pattern B)
BASIC SERVICE PROCEDURE
EC-77
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OPERATION PROCEDURE
With CONSULT-III
1. Start engine and warm it up to normal operation temperature.
2. Set shift lever in neutral position and confirm that following electrical or mechanical loads are not applied.
–Headlamp switch is OFF
–Air conditioner switch is OFF
–Rear defogger switch is OFF
–Steering wheel is in the straight-ahead position, etc
3. Keep the engine speed between 1,800 and 2,000 rpm.
4. Select “EXH V/T CONTROL LEARN” in “WORK SUPPORT” mode with CONSULT-III.
5. Touch “START” and wait 20 seconds.
6. Make sure that “CMPLT” is displayed on CONSULT-III screen.
Without CONSULT-III
1. Start engine and warm it up to normal operation temperature.
2. Set shift lever in neutral position and confirm that following electrical or mechanical loads are not applied.
–Headlamp switch is OFF
–Air conditioner switch is OFF
–Rear defogger switch is OFF
–Steering wheel is in the straight-ahead position, etc
3. Keep the engine speed between 1,800 and 2,000 rpm at 20 seconds.
Accelerator Pedal Released Position LearningNBS00039
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningNBS0003A
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningNBS0003B
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:
Each time electric throttle control actuator or ECM is replaced.
Learning completed : CMPLT
Learning not yet : YET
EC-78
BASIC SERVICE PROCEDURE
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Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
Battery voltage: More than 12.9V (At idle)
Engine coolant temperature: 70 - 100°C (158 - 212°F)
Park/neutral position (PNP) switch: ON
Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is started, the headlamp will not be illuminated.
Steering wheel: Neutral (Straight-ahead position)
Vehicle speed: Stopped
Transmission: Warmed-up
–For A/T models with CONSULT-III
Drive vehicle until “ATF TEMP SE 1” in “DATA MONITOR” mode of “A/T” system indicates less than 0.9V.
–For A/T models without CONSULT-III and M/T models
Drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-III
1. Perform EC-77, "Accelerator Pedal Released Position Learning" .
2. Perform EC-77, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
6. Touch “START” and wait 20 seconds.
7. Make sure that “CMPLT” is displayed on CONSULT-III screen. If “CMPLT” is not displayed, Idle Air Vol-
ume Learning will not be carried out successfully. In this case, find the cause of the incident by referring to
the DIAGNOSIS PROCEDURE below.
8. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
Without CONSULT-III
NOTE:
It is better to count the time accurately with a clock.
It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-77, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
ITEM SPECIFICATION
Idle speed A/T: 650 ± 50 rpm (in P or N position)
M/T: 650 ± 50 rpm (in Neutral position)
Ignition timing A/T: 15 ± 5° BTDC (in P or N position)
M/T: 15 ± 5° BTDC (in Neutral position)
BASIC SERVICE PROCEDURE
EC-79
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8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried
out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
DIAGNOSTIC PROCEDURE
If Idle Air Volume Learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2.Check PCV valve operation.
3.Check that downstream of throttle valve is free from air leakage.
4.When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-132, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5.If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:
Engine stalls.
Erroneous idle.
Fuel Pressure CheckNBS0003C
FUEL PRESSURE RELEASE
With CONSULT-III
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT” mode with CONSULT-III.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
ITEM SPECIFICATION
Idle speed A/T: 650 ± 50 rpm (in P or N position)
M/T: 650 ± 50 rpm (in Neutral position)
Ignition timing A/T: 15 ± 5° BTDC (in P or N position)
M/T: 15 ± 5° BTDC (in Neutral position)
SEC897C
EC-120
TROUBLE DIAGNOSIS
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*: This item is the same as that of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×: Applicable ENGINE SPEED
[rpm]
The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED
[km/h] or [mph]
The vehicle speed at the moment a malfunction is detected is displayed.
ABSOL TH-P/S [%]
The throttle valve operating angle at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec]
The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE
[°C] or [°F]
The intake air temperature at the moment a malfunction is detected is displayed. Freeze frame data
item*Description
Monitored item [Unit] Description Remarks
ENG SPEED [rpm]
Indicates the engine speed computed from the signals
of the crankshaft position sensor (POS) and camshaft
position sensor (PHASE).Accuracy becomes poor if engine speed drops
below the idle rpm.
If the signal is interrupted while the engine is
running, an abnormal value may be indicated.
MAS A/F SE-B1 [V]
The signal voltage of the mass air flow sensor is dis-
played.
When the engine is stopped, a certain value is
indicated.
When engine is running specification range is
indicated in “SPEC”. MAS A/F SE-B2 [V]
B/FUEL SCHDL [msec]
“Base fuel schedule” indicates the fuel injection pulse
width programmed into ECM, prior to any learned on
board correction.When engine is running specification range is
indicated in “SPEC”.
A/F ALPHA-B1 [%]
The mean value of the air-fuel ratio feedback correc-
tion factor per cycle is indicated.
When the engine is stopped, a certain value is
indicated.
This data also includes the data for the air-fuel
ratio learning control.
When engine is running specification range is
indicated in “SPEC”. A/F ALPHA-B2 [%]
COOLAN TEMP/S [°C]
or [°F]
The engine coolant temperature (determined by the
signal voltage of the engine coolant temperature sen-
sor) is displayed.When the engine coolant temperature sensor
is open or short-circuited, ECM enters fail-safe
mode. The engine coolant temperature deter-
mined by the ECM is displayed.
A/F SEN1 (B1) [V]
The A/F signal computed from the input signal of the
A/F sensor 1 is displayed.
A/F SEN1 (B2) [V]
HO2S2 (B1) [V]
The signal voltage of the heated oxygen sensor 2 is
displayed.
HO2S2 (B2) [V]
HO2S2 MNTR(B1)
[RICH/LEAN]
Display of heated oxygen sensor 2 signal:
RICH: Means the amount of oxygen after three way
catalyst is relatively small.
LEAN: Means the amount of oxygen after three way
catalyst is relatively large.
When the engine is stopped, a certain value is
indicated.
HO2S2 MNTR(B2)
[RICH/LEAN]
VHCL SPEED SE [km/
h] or [mph]
The vehicle speed computed from the vehicle speed
signal sent from combination meter is displayed.
BATTERY VOLT [V]
The power supply voltage of ECM is displayed.
ACCEL SEN 1 [V]
The accelerator pedal position sensor signal voltage is
displayed.ACCEL SEN 2 signal is converted by ECM
internally. Thus, it differs from ECM terminal
voltage signal. ACCEL SEN 2 [V]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-137
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11 . CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “SPEC” of "DATA MONITOR" mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 12.
12. CHECK A/F SENSOR 1 FUNCTION
Perform all DTC Confirmation Procedure related with A/F sensor 1.
For DTC P0130, P0150, refer to EC-248, "DTC Confirmation Procedure" .
For DTC P0131, P0151, refer to EC-267, "DTC Confirmation Procedure" .
For DTC P0132, P0152, refer to EC-660, "DTC Confirmation Procedure" .
For DTC P0133, P0153, refer to EC-276, "DTC Confirmation Procedure" .
For DTC P2A00, P2A03, refer to EC-660, "DTC Confirmation Procedure" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13. CHECK A/F SENSOR 1 CIRCUIT
Perform Diagnostic Procedure according to corresponding DTC.
>> GO TO 14.
14. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “SPEC” of "DATA MONITOR" mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 15.
15. DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “SPEC” of "DATA MONITOR" mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> Detect malfunctioning part according to EC-90, "
Symptom Matrix Chart" .
EC-138
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
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17. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of "DATA MONITOR" mode, and make sure that the indication is within the
SP value.
OK or NG
OK >>INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18. DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
–Engine oil level is too high
–Engine oil viscosity
–Belt tension of power steering, alternator, A/C compressor, etc. is excessive
–Noise from engine
–Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
–Valve clearance malfunction
–Intake valve timing control function malfunction
–Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19. CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
Crushed air ducts
Malfunctioning seal of air cleaner element
Uneven dirt of air cleaner element
Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
20. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “SPEC” of "DATA MONITOR" mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.
21. DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.