Misfires INFINITI FX35 2007 Service Manual

DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS- FIRE
EC-345
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS-
FIRE
PFP:00000
On Board Diagnosis LogicNBS003PY
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 second 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 second trip. During this condition, the ECM monitors the CKP sen-
sor 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
0300 Multiple cylinder misfire
detected Multiple cylinder misfire.

Improper spark plug

Insufficient compression

Incorrect fuel pressure

Fuel injector circuit is open or shorted

Fuel injector

Intake air leak

Ignition signal circuit is open or shorted

Lack of fuel

Signal plate

Air fuel ratio (A/F) sensor 1

Incorrect PCV hose connection
P0301
0301 No.1 cylinder misfire
detected No. 1 cylinder misfires.
P0302
0302 No. 2 cylinder misfire
detected No. 2 cylinder misfires.
P0303
0303 No. 3 cylinder misfire
detected No. 3 cylinder misfires.
P0304
0304 No. 4 cylinder misfire
detected No. 4 cylinder misfires.
P0305
0305 No. 5 cylinder misfire
detected No. 5 cylinder misfires.
P0306
0306 No. 6 cylinder misfire
detected No. 6 cylinder misfires.

EC-1016
[VK45DE]
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS- FIRE
Revision: 2006 July 2007 FX35/FX45
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
PFP:00000
On Board Diagnosis LogicNBS0046X
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 first 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 second 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 second trip. During this condition, the ECM monitors the CKP sen-
sor 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
0300 Multiple cylinder misfire
detected Multiple 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

Drive plate

A/F sensor 1

Incorrect PCV hose connection
P0301
0301 No.1 cylinder misfire
detected No. 1 cylinder misfires.
P0302
0302 No. 2 cylinder misfire
detected No. 2 cylinder misfires.
P0303
0303 No. 3 cylinder misfire
detected No. 3 cylinder misfires.
P0304
0304 No. 4 cylinder misfire
detected No. 4 cylinder misfires.
P0305
0305 No. 5 cylinder misfire
detected No. 5 cylinder misfires.
P0306
0306 No. 6 cylinder misfire
detected No. 6 cylinder misfires.
P0307
0307 No. 7 cylinder misfire
detected No. 7 cylinder misfires.
P0308
0308 No. 8 cylinder misfire
detected No. 8 cylinder misfires.