NISSAN ALMERA N16 2003 Electronic Repair Manual

13 CHECK ECM POWER SUPPLY CIRCUIT-V
1. Turn ignition switch “OFF”.
2. Disconnect ECM relay. (For ECM relay location, refer to “Engine ControlComponent Parts Location”.)
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminals 107, 108, 109 and ECM relay terminal 7. Refer to Wiring Diagram.
Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG
OK GO TO 15.
NG GO TO 14.
14 DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E75, F36
Harness for open or short between ECM and ECM relay
Repair open circuit or short to ground or short to power in harness or connectors.
15 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminals 104, 105, 106 and engineground. Refer to Wiring Diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK GO TO 16.
NG Repair open circuit or short to ground or short to power in harness or connectors.
16 CHECK INTERMITTENT INCIDENT
Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-71.
INSPECTION END
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TROUBLE DIAGNOSIS FOR POWER SUPPLYYD
Main Power Supply and Ground Circuit (Cont’d)
EC-77

SEF987W
Component DescriptionNJEC0642The mass air flow sensor (MAFS) is placed in the stream of intake
air. It measures the intake air flow rate by measuring a part of the
entire intake air flow. It consists of a hot film that is supplied with
electric current from the ECM. The temperature of the hot film is
controlled by the ECM a certain amount. The heat generated by the
hot film is reduced as the intake air flows around it. The more air,
the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0643Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SEEngine: After warming up
Air conditioner switch: “OFF”
Shift lever: Neutral position
No-loadIdle 1.5 - 2.0V
ECM Terminals and Reference ValueNJEC0644Specification data are reference values, and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM’s transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
218 B Sensor’s ground[Engine is running]
Warm-up condition
Idle speedApproximately 0V
223 WMass air flow sensor
power supply[Ignition switch “ON”]Approximately 5V
224 R Mass air flow sensor[Engine is running]
Warm-up condition
Idle speed1.5 - 2.0V
On Board Diagnosis LogicNJEC0645This self-diagnosis has the one trip detection logic.
DTC Malfunction is detected when ... Check Items (Possible Cause)
P0100
0102An excessively high or low voltage from the sen-
sor is sent to ECM.Harness or connectors
(The sensor circuit is open or shorted.)
Mass air flow sensor
DTC P0100 MASS AIR FLOW SENYD
Component Description
EC-78

SEF817Y
DTC Confirmation ProcedureNJEC0646WITH CONSULT-IINJEC0646S011) Turn ignition switch “ON”, and wait at least 6 seconds.
2) Select “DATA MONITOR” mode with CONSULT-II.
3) Start engine and wait at least 3 seconds.
4) If DTC is detected, go to “Diagnostic Procedure”, EC-81.
WITHOUT CONSULT-IINJEC0646S021) Turn ignition switch “ON”, and wait at least 6 seconds.
2) Start engine and wait at least 3 seconds.
3) Turn ignition switch “OFF”, wait at least 5 seconds and then
turn “ON”.
4) Perform “Diagnostic Test Mode II (Self-diagnostic results)” with
ECM.
5) If DTC is detected, go to “Diagnostic Procedure”, EC-81.
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DTC P0100 MASS AIR FLOW SENYD
DTC Confirmation Procedure
EC-79

Wiring DiagramNJEC0647
YEC322A
DTC P0100 MASS AIR FLOW SENYD
Wiring Diagram
EC-80

Diagnostic ProcedureNJEC0648
1 CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect mass air flow sensor harness connector.
SEF884Y
3. Turn ignition switch “ON”.
4. Check voltage between mass air flow sensor terminals 2, 4 and ground withCONSULT-II or tester.
SEF297X
OK or NG
OK GO TO 3.
NG GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E75, F36
Harness for open or short between mass air flow sensor and ECM
Harness for open or short between mass air flow sensor and ECM relay
Repair open circuit or short to ground or short to power in harness or connector.
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DTC P0100 MASS AIR FLOW SENYD
Diagnostic Procedure
EC-81

3 CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
SEF380Y
3. Check harness continuity between mass air flow sensor terminal 3 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK GO TO 5.
NG GO TO 4.
4 DETECT MALFUNCTIONING PART
Check harness for open or short between mass air flow sensor and ECM.
Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor terminal 1 and ECMterminal 224. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK GO TO 6.
NG Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0100 MASS AIR FLOW SENYD
Diagnostic Procedure (Cont’d)
EC-82

6 CHECK MASS AIR FLOW SENSOR
1. Reconnect harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 224 (Mass air flow sensor signal) andground.
SEF441Z
4. If the voltage is out of specification, disconnect MAFS harness connector and connect it again.
Then repeat above check.
OK or NG
OK GO TO 7.
NG Replace mass air flow sensor.
7 CHECK INTERMITTENT INCIDENT
Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-71.
INSPECTION END
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DTC P0100 MASS AIR FLOW SENYD
Diagnostic Procedure (Cont’d)
EC-83

SEF594K
DescriptionNJEC0649The engine coolant temperature sensor is used to detect the
engine coolant temperature. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the
engine coolant temperature input. The sensor uses a thermistor
which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
SEF012P
<Reference data>
Engine coolant tempera-
ture °C (°F)Voltage* (V) Resistance (kΩ)
−10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.3 0.68 - 1.00
90 (194) 1.0 0.236 - 0.260
*: These data are reference values and measured between ECM terminal 347
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM’s
transistor. Use a ground other than ECM terminals, such as
the ground.
On Board Diagnosis LogicNJEC0650This self-diagnosis has the one trip detection logic.
DTC Malfunction is detected when ... Check Items (Possible Cause)
P0115
0103An excessively high or low voltage from the sen-
sor is entered to ECM.Harness or connectors (The sensor circuit is
open or shorted.)
Engine coolant temperature sensor
SEF817Y
DTC Confirmation ProcedureNJEC0651WITH CONSULT-IINJEC0651S011) Turn ignition switch “ON”.
2) Select “DATA MONITOR” mode with CONSULT-II.
3) Wait at least 5 seconds.
4) If DTC is detected, go to “Diagnostic Procedure”, EC-87.
WITHOUT CONSULT-IINJEC0651S021) Turn ignition switch “ON” and wait at least 5 seconds.
2) Turn ignition switch “OFF”, wait at least 5 seconds and then
turn “ON”.
DTC P0115 COOLANT TEMP SENYD
Description
EC-84

3) Perform “Diagnostic Test Mode II (Self-diagnostic results)” with
ECM.
4) If DTC is detected, go to “Diagnostic Procedure”, EC-87.
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DTC P0115 COOLANT TEMP SENYD
DTC Confirmation Procedure (Cont’d)
EC-85

Wiring DiagramNJEC0652
YEC011A
DTC P0115 COOLANT TEMP SENYD
Wiring Diagram
EC-86