2003 NISSAN ALMERA N16 ecm

Main Power Supply and Ground Circuit
ECM TERMINALS AND REFERENCE VALUENJEC0639Remarks: Specification 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.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA(DC Voltage)
104
105
106B
B
BECM ground[Engine is running]
Idle speedApproximately 0V
107
108
109R
R
RPower supply for ECM[Ignition switch “ON”]BATTERY VOLTAGE
(11 - 14V)
325 G ECM relay (Self-shutoff)[Ignition switch “ON”]
[Ignition switch “OFF”]
For a few seconds after turning ignition switch
“OFF”Approximatley 0.25V
[Ignition switch “OFF”]
A few seconds passed after turning ignition switch
“OFF”BATTERY VOLTAGE
(11 - 14V)
507 W/R Ignition switch[Ignition switch “OFF”]0V
[Ignition switch “ON”]BATTERY VOLTAGE
(11 - 14V)
TROUBLE DIAGNOSIS FOR POWER SUPPLYYD
Main Power Supply and Ground Circuit
EC-72

DIAGNOSTIC PROCEDURENJEC0641
1 INSPECTION START
Start engine.
Is engine running?
YesorNo
Yes GO TO 13.
No GO TO 2.
2 CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch “ON”.
2. Check voltage between ECM terminal 507 and ground with CONSULT-II or tester.
SEF895Y
OK or NG
OK GO TO 4.
NG GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
Harness connectors M74, F112
Fuse block (J/B) connector M1
10A fuse
Harness for open or short between ECM and fuse
Repair open circuit or short to ground or short to power in harness or connectors.
4 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals 104, 105, 106 and engineground. 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 Repair open circuit or short to ground or short to power in harness or connectors.
TROUBLE DIAGNOSIS FOR POWER SUPPLYYD
Main Power Supply and Ground Circuit (Cont’d)
EC-74

5 CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch “ON” and then “OFF”.
3. Check voltage between ECM terminals 107, 108, 109 and ground with CONSULT-II or tester.
SEF896Y
OK or NG
OK Check electronic control fuel injection pump power supply circuit. Refer to “Diagnostic
Procedure”, EC-173.
NG (Battery voltage
does not exist.)GO TO 6.
NG (Battery voltage
exists for more than a
few seconds.)GO TO 10.
6 CHECK ECM POWER SUPPLY CIRCUIT-III
1. Disconnect ECM relay. (For ECM relay location, refer to “Engine ControlComponent Parts Location”.)
2. Check voltage between relay terminals 1, 6 and ground with CONSULT-II ortester.
SEF399Y
OK or NG
OK GO TO 8.
NG GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
20A fuse
10A fuse
Harness for open or short between ECM relay and battery
Repair open circuit or short to ground or short to power in harness or connectors.
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TROUBLE DIAGNOSIS FOR POWER SUPPLYYD
Main Power Supply and Ground Circuit (Cont’d)
EC-75

8 CHECK OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 325 and ECM relay terminal 2. 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 10.
NG GO TO 9.
9 DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E174, M159 (LHD models)
Harness connectors E251, M182 (RHD models)
Harness connectors M63, F102
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.
10 CHECK ECM POWER SUPPLY CIRCUIT-IV
1. Check harness continuity between ECM terminals 107, 108, 109 and ECM relay terminal 7. 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 12.
NG GO TO 11.
11 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.
12 CHECK ECM RELAY
1. Apply 12V direct current between ECM relay terminals 1 and 2.
2. Check continuity between ECM relay terminals 3 and 5, 7 and 6.
SEF296X
OK or NG
OK GO TO 16.
NG Replace ECM relay.
TROUBLE DIAGNOSIS FOR POWER SUPPLYYD
Main Power Supply and Ground Circuit (Cont’d)
EC-76

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

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