AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-31
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Revision: 2006 November2007 350Z
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed after cancel operation other than pressing MAIN switch
is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must
meet following conditions.
Brake pedal is released
Clutch pedal is released (M/T models)
A/T selector lever is in other than P and N positions (A/T models)
Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component DescriptionNBS0002N
ASCD STEERING SWITCH
Refer to EC-602
ASCD BRAKE SWITCH
Refer to EC-610 and EC-671 .
ASCD CLUTCH SWITCH
Refer to EC-610 and EC-671 .
STOP LAMP SWITCH
Refer to EC-610 , EC-628 and EC-671 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-561 , EC-571 , EC-580 and EC-592 .
ASCD INDICATOR
Refer to EC-681 .
EC-44
POSITIVE CRANKCASE VENTILATION
Revision: 2006 November2007 350Z
POSITIVE CRANKCASE VENTILATIONPFP:11810
DescriptionNBS0002W
SYSTEM DESCRIPTION
This system returns blow-by gas to the intake manifold.
The positive crankcase ventilation (PCV) valve is provided to conduct crankcase blow-by gas to the intake
manifold. During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the
PCV valve. Normally, the capacity of the valve is sufficient to handle any blow-by and a small amount of venti-
lating air. The ventilating air is then drawn from the air inlet tubes into the crankcase. In this process the air
passes through the hose connecting air inlet tubes to rocker cover. Under full-throttle condition, the manifold
vacuum is insufficient to draw the blow-by flow through the valve. The flow goes through the hose connection
in the reverse direction.
On vehicles with an excessively high blow-by, the valve does not
meet the requirement. This is because some of the flow will go
through the hose connection to the air inlet tubes under all condi-
tions.
1. PCV valve 2. Electric throttle control actuator 3. Mass air flow sensor
A. Normal condition B. Hi-load condition
:Fresh air
:Blow-by air
PBIB3536E
PBIB1588E
EC-48
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2006 November2007 350Z
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
Emission-related Diagnostic InformationNBS00031
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
×: Applicable —: Not applicable Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
Items
(CONSULT-III screen terms)DTC*
1
SRT codeTest value/
Te s t l i m i t
(GST only)TripMIL lighting
upReference
page CONSULT-III
GST*
2ECM*3
CAN COMM CIRCUIT U1000
1000*5—— 1×EC-151
CAN COMM CIRCUIT U1001
1001*5—— 2 —EC-151
CONTROL UNIT(CAN) U1010 1010 — —1 (A/T)× (A/T)
EC-1542 (M/T) — (M/T)
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.P0000 0000—— —
Flashing*
7EC-63
INT/V TIM CONT-B1 P0011 0011 — — 2×EC-156
EXH/V TIM CONT-B1 P0014 0014 — — 2×EC-160
INT/V TIM CONT-B2 P0021 0021 — — 2×EC-156
EXH/V TIM CONT-B2 P0024 0024 — — 2×EC-160
A/F SEN1 HTR (B1) P0031 0031 —×2×EC-165
A/F SEN1 HTR (B1) P0032 0032 —×2×EC-165
HO2S2 HTR (B1) P0037 0037 —×2×EC-173
HO2S2 HTR (B1) P0038 0038 —×2×EC-173
A/F SEN1 HTR (B2) P0051 0051 —×2×EC-165
A/F SEN1 HTR (B2) P0052 0052 —×2×EC-165
HO2S2 HTR (B2) P0057 0057 —×2×EC-173
HO2S2 HTR (B2) P0058 0058 —×2×EC-173
INT/V TIM V/CIR-B1 P0075 0075 — — 2×EC-183
EX V/T MGT/RTDR-B1 P0078 0078 — — 2×EC-190
INT/V TIM V/CIR-B2 P0081 0081 — — 2×EC-183
EX V/T MGT/RTDR-B2 P0084 0084 — — 2×EC-190
MAF SEN/CIRCUIT-B1 P0101 0101 — — 2×EC-197
MAF SEN/CIRCUIT-B1 P0102 0102 — — 1×EC-208
MAF SEN/CIRCUIT-B1 P0103 0103 — — 1×EC-208
MAF SEN/CIRCUIT-B2 P010B 010B — — 2×EC-197
MAF SEN/CIRCUIT-B2 P010C 010C — — 1×EC-208
MAF SEN/CIRCUIT-B2 P010D 010D — — 1×EC-208
IAT SEN/CIRCUIT-B1 P0112 0112 — — 2×EC-218
IAT SEN/CIRCUIT-B1 P0113 0113 — — 2×EC-218
ECT SEN/CIRC P0117 0117 — — 1×EC-223
ECT SEN/CIRC P0118 0118 — — 1×EC-223
TP SEN 2/CIRC-B1 P0122 0122 — — 1×EC-229
TP SEN 2/CIRC-B1 P0123 0123 — — 1×EC-229
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-53
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If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-III screen, not on the GST. For
details, see EC-119, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (Priority: 2) was detected and the freeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st trip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If freeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM memory are described in EC-61, "
HOW TO ERASE EMIS-
SION-RELATED DIAGNOSTIC INFORMATION" .
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979.
As part of an enhanced emissions test for Inspection & Maintenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MIL is ON during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. Therefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
Priority Items
1Freeze frame data Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-63
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When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
MIL Flashing Without DTC
When any SRT codes are not set, MIL may flash without DTC. For the details, refer to EC-56, "How to Display
SRT Status" .
HOW TO SWITCH DIAGNOSTIC TEST MODE
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.
Always ECM returns to Diagnostic Test Mode I after ignition switch is turned OFF.
How to Set Diagnostic Test Mode II (Self-diagnostic Results)
1. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
2. Repeat the following procedure quickly 5 times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MIL starts
blinking.
Diagnostic Test
ModeKEY and ENG.
StatusFunction Explanation of Function
Mode I Ignition switch in
ON position
Engine stoppedBULB CHECK This function checks the MIL bulb for damage (blown,
open circuit, etc.).
If the MIL does not come on, check MIL circuit.
Engine running MALFUNCTION
WARNINGThis is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MIL will light up to inform the driver
that a malfunction has been detected.
The following malfunctions will light up or blink the MIL in
the 1st trip.
Misfire (Possible three way catalyst damage)
One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stoppedSELF-DIAGNOSTIC
RESULTSThis function allows DTCs and 1st trip DTCs to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
EC-72
BASIC SERVICE PROCEDURE
Revision: 2006 November2007 350Z
3. CHECK TARGET IDLE SPEED
With CONSULT-III
1. Run engine at about 2,000 rpm for about 2 minutes under no-load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no-
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-III.
Refer to EC-76, "
IDLE SPEED" .
Without CONSULT-III
1. Run engine at about 2,000 rpm for about 2 minutes under no-
load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no-
load, then run engine at idle speed for about 1 minute.
3. Check idle speed. Refer to EC-76, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-77, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
6. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-77, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4. A/T: 650 ± 50 rpm (in P or N position)
M/T: 650 ± 50 rpm (in Neutral position)
A/T: 650 ± 50 rpm (in P or N position)
M/T: 650 ± 50 rpm (in Neutral position)
SEF978U
EC-74
BASIC SERVICE PROCEDURE
Revision: 2006 November2007 350Z
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-77, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-77, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-III.
Refer to EC-76, "
IDLE SPEED" .
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed. Refer to EC-76, "
IDLE SPEED" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15. CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-76, "
IGNITION TIMING" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 16.A/T: 650 ± 50 rpm (in P or N position)
M/T: 650 ± 50 rpm (in Neutral position)
A/T: 650 ± 50 rpm (in P or N position)
M/T: 650 ± 50 rpm (in Neutral position)
A : Timing indicator
A/T: 15 ± 5° BTDC (in P or N position)
M/T: 15 ± 5° BTDC (in Neutral position)
PBIB3530E
EC-76
BASIC SERVICE PROCEDURE
Revision: 2006 November2007 350Z
Idle Speed and Ignition Timing CheckNBS00035
IDLE SPEED
With CONSULT-III
Check idle speed in “DATA MONITOR” mode with CONSULT-III.
With GST
Check idle speed in Service $01 with GST.
IGNITION TIMING
1. Attach timing light to loop wire as shown.
2. Check ignition timing.
Procedure After Replacing ECMNBS006SZ
When replacing ECM, the following procedure must be performed.
1. Perform initialization of NVIS (NATS) system and registration of all NVIS (NATS) ignition key IDs. Refer to
BL-152, "
ECM Re-communicating Function" .
2. Perform EC-76, "
VIN Registration" .
3. Perform EC-76, "
Exhaust Valve Timing Control Learning" .
4. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-77, "
Throttle Valve Closed Position Learning" .
6. Perform EC-77, "
Idle Air Volume Learning" .
VIN RegistrationNBS00037
DESCRIPTION
VIN Registration is an operation to registering VIN in ECM. It must be performed each time ECM is replaced.
NOTE:
Accurate VIN which is registered in ECM may be required for Inspection & Maintenance (I/M).
OPERATION PROCEDURE
With CONSULT-III
1. Check the VIN of the vehicle and note it. Refer to GI-46, "IDENTIFICATION INFORMATION" .
2. Turn ignition switch ON and engine stopped.
3. Select “VIN REGISTRATION” in “WORK SUPPORT” mode.
4. Follow the instruction of CONSULT-III display.
Exhaust Valve Timing Control LearningNBS00038
DESCRIPTION
Exhaust Valve Timing Control Learning is an operation to learn the characteristic of exhaust valve timing con-
trol magnet retarder by comparing the target angle of exhaust camshaft with the actual retarded angle of
exhaust camshaft. It must be performed each time exhaust valve timing control magnet retarder is discon-
nected or replaced, or ECM is replaced.
1. Loop wire
A. Timing light B. Timing indicator
PBIB3526E