2001 NISSAN ALMERA ignition

2 CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ªOFFº and then ªONº.
2. Check voltage between ECM terminal 43 and ground with CONSULT-II or tester.
SEF291X
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E74, F35 (If so equipped)
+Harness connectors M21, E106 (Sedan), M160, E175 or M169, F113 (Hatchback)
+Fuse block (J/B) connector M1, E103
+10A fuse
+Harness for open or short between ECM and ignition switch
©Repair harness or connectors.
4 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals 48, 57, 106, 108 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©Repair open circuit or short to ground or short to power in harness or connectors.
TROUBLE DIAGNOSIS FOR POWER SUPPLYQG
Main Power Supply and Ground Circuit (Cont'd)
EC-182

5 CHECK POWER SUPPLY-II
1. Disconnect ECM relay. (For ECM relay location, refer to ªEngine Control Compartment Parts Locationº.)
2. Check voltage between ECM relay terminals 1, 6 and ground with CONSULT-II or tester.
SEF101Y
OK or NG
OK©GO TO 7.
NG©GO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
+15A fuse and 10A fuse
+Harness connectors E75, F36 (If so equipped)
+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.
7 CHECK OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 31 and ECM relay terminal 2.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK©Go to ªIGNITION SIGNALº, EC-547.
NG©GO TO 8.
8 DETECT MALFUNCTIONING PART
Check the harness for open or short between ECM relay and ECM.
©Repair open circuit or short to ground or short to power in harness or connectors.
TROUBLE DIAGNOSIS FOR POWER SUPPLYQG
Main Power Supply and Ground Circuit (Cont'd)
EC-183

9 CHECK ECM POWER SUPPLY CIRCUIT-II
1. Stop engine.
2. Check voltage between ECM terminal 67 and ground with CONSULT-II or tester.
SEF293X
OK or NG
OK©GO TO 11.
NG©GO TO 10.
10 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E75, F36 (If so equipped)
+Harness for open or short between ECM and fuse
©Repair harness or connectors.
11 CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch ªONº and then ªOFFº.
2. Check voltage between ECM terminals 110, 112 and ground with CONSULT-II or tester.
SEF294X
OK or NG
OK©GO TO 17.
NG (Battery voltage
does not exist.)©GO TO 12.
NG (Battery voltage
exists for more than a
few seconds.)©GO TO 14.
TROUBLE DIAGNOSIS FOR POWER SUPPLYQG
Main Power Supply and Ground Circuit (Cont'd)
EC-184

16 CHECK ECM RELAY
1. Apply 12V direct current between ECM relay terminals 1 and 2.
2. Check continuity between relay terminals 3 and 5, 6 and 7.
SEF296X
OK or NG
OK©GO TO 17.
NG©Replace ECM relay.
17 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals 48, 57, 106, 108 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 18.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
18 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
TROUBLE DIAGNOSIS FOR POWER SUPPLYQG
Main Power Supply and Ground Circuit (Cont'd)
EC-186

Fail-safe ModeNJEC0589
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuitEngine speed will not rise more than 2,400 rpm due to the fuel
cut.
DTC Confirmation ProcedureNJEC0054CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
SEF058Y
PROCEDURE FOR MALFUNCTION ANJEC0054S01With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 2 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-191.
With GST
Follow the procedure ªWith CONSULT-IIº above.
SEF058Y
PROCEDURE FOR MALFUNCTION BNJEC0054S02With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and wait 2 seconds at most.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-191.
With GST
Follow the procedure ªWith CONSULT-IIº above.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Fail-safe Mode
EC-188

Diagnostic ProcedureNJEC0057
1 INSPECTION START
Which malfunction (A, or B) is duplicated?
Malfunction A or B
A©GO TO 3.
B©GO TO 2.
2 CHECK INTAKE SYSTEM
Check the following for connection.
+Air duct
+Vacuum hoses
+Intake air passage between air duct to collector
OK or NG
OK©GO TO 3.
NG©Reconnect the parts.
3 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
JEF104Y
©GO TO 4.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Diagnostic Procedure
EC-191

4 CHECK POWER SUPPLY
1. Disconnect mass air flow sensor harness connector.
JEF105Y
2. Turn ignition switch ªONº.
3. Check voltage between terminal 2, 4 and ground with CONSULT-II or tester.
SEF297X
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-4 (If so equipped)
+Joint connector-6 (If so equipped)
+Harness for open or short between ECM relay and mass air flow sensor
+Harness for open or short between mass air flow sensor and ECM
©Repair harness or connectors.
6 CHECK GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass air flow sensor harness connector terminal 3 and ECM terminal 73.
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 7.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Diagnostic Procedure (Cont'd)
EC-192

7 CHECK INPUT SIGNAL CIRCUIT
1. Check harness continuity between mass air flow sensor harness connector terminal 1 and ECM terminal 61.
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 8.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK MASS AIR FLOW SENSOR
Refer to ªComponent Inspectionº, EC-193.
OK or NG
OK©GO TO 9.
NG©Replace mass air flow sensor.
9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
SEF993W
SEF987W
Component InspectionNJEC0058MASS AIR FLOW SENSORNJEC0058S011. Turn ignition switch ªONº.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 61 (Mass air flow sen-
sor signal) and ground.
Conditions Voltage V
Ignition switch ªONº (Engine stopped.) Less than 1.2
Idle (Engine is warmed-up to normal operating
temperature.)1.0 - 1.7
2,500 rpm (Engine is warmed-up to normal oper-
ating temperature.)1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.7 to Approx. 4.0
*: Check for linear voltage rise in response to increases to about 4,000 rpm in
engine speed.
4. If the voltage is out of specification, disconnect mass air flow
sensor harness connector and connect it again. Repeat above
check.
5. If NG, remove mass air flow sensor from air duct. Check hot
film for damage or dust.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Diagnostic Procedure (Cont'd)
EC-193