EC-124
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
ACTIVE TEST MODE
Test Item
*: Leaving cooling fan “OFF” with CONSULT-III while engine is running may cause the engine to overheat.TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION
Engine: Return to the original
trouble condition
Change the amount of fuel injec-
tion using CONSULT-III.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Fuel injector
Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING
Engine: Return to the original
trouble condition
Timing light: Set
Retard the ignition timing using
CONSULT-III.If trouble symptom disappears, see
CHECK ITEM.
Perform Idle Air Volume Learning.
POWER BAL-
ANCE
Engine: After warming up, idle
the engine.
A/C switch OFF
Shift lever: P or N (A/T), Neutral
(M/T)
Cut off each fuel injector signal
one at a time using CONSULT-III.Engine runs rough or dies.
Harness and connectors
Compression
Fuel injector
Power transistor
Spark plug
Ignition coil
COOLING FAN
*
Ignition switch: ON
Turn the cooling fan “HI”, “LOW”
and “OFF” using CONSULT-III.Cooling fan moves and stops.
Harness and connectors
Cooling fan motor
IPDM E/R
ENG COOLANT
TEMP
Engine: Return to the original
trouble condition
Change the engine coolant tem-
perature using CONSULT-III.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Engine coolant temperature sen-
sor
Fuel injector
FUEL PUMP
RELAY
Ignition switch: ON
(Engine stopped)
Turn the fuel pump relay “ON”
and “OFF” using CONSULT-III
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.Harness and connectors
Fuel pump relay
PURG VOL
CONT/V
Engine: After warming up, run
engine at 1,500 rpm.
Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-III.Engine speed changes according to
the opening percent.Harness and connectors
Solenoid valve
FUEL/T TEMP
SEN
Change the fuel tank temperature using CONSULT-III.
VENT CON-
TROL/V
Ignition switch: ON
(Engine stopped)
Turn solenoid valve “ON” and
“OFF” with the CONSULT-III and
listen to operating sound.Solenoid valve makes an operating
sound.Harness and connectors
Solenoid valve
INT V/T ASSIGN
ANGLE
Engine: Return to the original
trouble condition
Change intake valve timing using
CONSULT-III.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Intake valve timing control sole-
noid valve
EXH V/T ASSIGN
ANGLE
Engine: Return to the original
trouble condition
Change exhaust valve timing
using CONSULT-III.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Exhaust valve timing control mag-
net retarder
DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS-
FIRE
EC-371
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2006 November2007 350Z
DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS-
FIRE
PFP:00000
On Board Diagnosis LogicNBS0007U
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary, ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the 1st trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-
heating, the MIL will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC on a 2nd trip, the MIL will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only
light when the misfire is detected on a 2nd trip. During this condition, the ECM monitors the CKP sensor
signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300
0300Multiple cylinder misfire
detectedMultiple cylinder misfire.
Improper spark plug
Insufficient compression
Incorrect fuel pressure
The fuel injector circuit is open or
shorted
Fuel injector
Intake air leak
The ignition signal circuit is open or
shorted
Lack of fuel
Signal plate
Air fuel ratio (A/F) sensor 1
Incorrect PCV hose connection P0301
0301No.1 cylinder misfire
detectedNo. 1 cylinder misfires.
P0302
0302No. 2 cylinder misfire
detectedNo. 2 cylinder misfires.
P0303
0303No. 3 cylinder misfire
detectedNo. 3 cylinder misfires.
P0304
0304No. 4 cylinder misfire
detectedNo. 4 cylinder misfires.
P0305
0305No. 5 cylinder misfire
detectedNo. 5 cylinder misfires.
P0306
0306No. 6 cylinder misfire
detectedNo. 6 cylinder misfires.
