Page 550 of 720

EC-550
DTC P1217 ENGINE OVER TEMPERATURE
Revision: 2006 November2007 350Z
5. CHECK COOLING FAN HIGH SPEED OPERATION
Without CONSULT-III
1. Turn ignition switch OFF.
2. Turn air conditioner switch and blower fan switch OFF.
3. Disconnect engine coolant temperature sensor harness connector.
4. Connect 150Ω resistor to engine coolant temperature sensor harness connector.
5. Restart engine and make sure that cooling fans-1 and -2 oper-
ate at higher speed than low speed.
OK or NG
OK >> GO TO 6.
NG >> Check cooling fan high speed control circuit. (Go to EC-
554, "PROCEDURE B" .)
6. CHECK COOLING SYSTEM FOR LEAK
Refer to CO-10, "
LEAK CHECK" .
OK or NG
OK >> GO TO 7.
NG >> Check the following for leak.
Hose
Radiator
Water pump
7. CHECK RADIATOR CAP
Refer to CO-15, "
Checking Radiator Cap" .
OK or NG
OK >> GO TO 8.
NG >> Replace radiator cap.
8. CHECK THERMOSTAT
Refer to CO-26, "
WATER INLET AND THERMOSTAT ASSEMBLY" .
OK or NG
OK >> GO TO 9.
NG >> Replace thermostat
9. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-228, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace engine coolant temperature sensor.
10. CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to EC-555, "
Main 12 Causes of Overheating" .
>>INSPECTION END
MEC475B
Page 555 of 720

DTC P1217 ENGINE OVER TEMPERATURE
EC-555
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2006 November2007 350Z
4. CHECK INTERMITTENT INCIDENT
Perform EC-141, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R. Refer to PG-16, "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MOD-
ULE ENGINE ROOM)" .
NG >> Repair or replace harness or connectors.
Main 12 Causes of OverheatingNBS000DK
*1: Turn the ignition switch ON.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to CO-6, "
OVERHEATING CAUSE ANALYSIS" . Engine Step Inspection item Equipment Standard Reference page
OFF 1
Blocked radiator
Blocked condenser
Blocked radiator grille
Blocked bumper
Visual No blocking —
2
Coolant mixtureCoolant tester 50 - 50% coolant mixtureMA-12
3Coolant levelVisual Coolant up to MAX level
in reservoir tank and radi-
ator filler neckCO-10
4Radiator capPressure tester 88 - 127 kPa
(0.90 - 1.30 kg/cm2 , 12.8
- 18.4 psi) (Limit)CO-15
ON*25Coolant leaksVisual No leaksCO-10
ON*26ThermostatTouch the upper and
lower radiator hosesBoth hoses should be hotCO-26
ON*17Cooling fanCONSULT-III Operating See trouble diagnosis for
DTC P1217 (EC-543
).
OFF 8
Combustion gas leakColor checker chemical
tester 4 Gas analyzerNegative —
ON*
39Coolant temperature
gaugeVisual Gauge less than 3/4
when driving—
Coolant overflow to
reservoir tankVisual No overflow during driving
and idlingCO-10
OFF*410Coolant return from
reservoir tank to radia-
torVisual Should be initial level in
reservoir tankCO-10
OFF 11Cylinder headStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)EM-89
12Cylinder block and pis-
tonsVisual No scuffing on cylinder
walls or pistonEM-107
Page 600 of 720

EC-600
DTC P1421 COLD START CONTROL
Revision: 2006 November2007 350Z
DTC P1421 COLD START CONTROLPFP:23710
DescriptionNBS006TX
ECM controls ignition timing and engine idle speed when engine is started with prewarming up condition.
This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.
On Board Diagnosis LogicNBS006TY
DTC Confirmation ProcedureNBS006TZ
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
If DTC P1421 is displayed with other DTC, first perform the trouble diagnosis for other DTC.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Check that the “COOLAN TEMP/S” indication is between 4°C (39°F) and 36°C (97°F).
If “COOLAN TEMP/S” indication is within the specified value, go to the following step.
If “COOLANT TEMP/S” indication is out of the specified value, cool engine down or warm engine up and
go to step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-600, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnostic ProcedureNBS006U0
1. PERFORM IDLE AIR VOLUME LEARNING
Perform EC-77, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 2.
No >> Follow the instruction of Idle Air Volume Learning.
2. CHECK INTAKE SYSTEM
Check for the cause of intake air volume lacking. Refer to the following.
Crushed intake air passage
Intake air passage clogging
OK or NG
OK >> GO TO 3.
NG >> Repair or replace malfunctioning part
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1421
1421Cold start emission reduction
strategy monitoringECM does not control ignition timing and engine
idle speed properly when engine is started with
prewarming up condition.
Lack of intake air volume
Fuel injection system
ECM
Page 718 of 720

EC-718
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: 2006 November2007 350Z
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureNBS000IJ
Idle Speed and Ignition TimingNBS000IK
*: Under the following conditions:
Air conditioner switch: OFF
Electric load: OFF (Lights, heater fan & rear window defogger)
Steering wheel: Kept in straight-ahead position
Calculated Load ValueNBS000IL
Mass Air Flow SensorNBS000IM
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorNBS000IN
Engine Coolant Temperature SensorNBS000IO
Air Fuel Ratio (A/F) Sensor 1 HeaterNBS000IP
Heated Oxygen sensor 2 HeaterNBS000IQ
Crankshaft Position Sensor (POS)NBS000IR
Refer to EC-393, "Component Inspection" .
Camshaft Position Sensor (PHASE)NBS000IS
Refer to EC-405, "Component Inspection" .
Fuel pressure at idling kPa (kg/cm2 , psi)Approximately 350 (3.57, 51)
Target idle speedA/T No load* (in P or N position)
650 ± 50 rpm
M/T No load* (in Neutral position)
Air conditioner: ONA/T In P or N position 650 rpm or more
M/T In Neutral position 800 rpm or more
Ignition timingA/T In P or N position
15° ± 5° BTDC
M/T In Neutral position
Conditions Calculated load value % (Using CONSULT-III or GST)
At idle5 - 35
At 2,500 rpm5 - 35
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle0.8 - 1.1V*
Mass air flow (Using CONSULT-III or GST)2.0 - 6.0 g·m/sec at idle*
7.0 - 20.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.800 - 2.200
Temperature °C (°F) Resistance kΩ
20 (68)2.37 - 2.63
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Resistance [at 25°C (77°F)] 1.8 - 2.44Ω
Resistance [at 25°C (77°F)] 3.4 - 4.4Ω