Page 145 of 720

POWER SUPPLY AND GROUND CIRCUIT
EC-145
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Revision: 2006 November2007 350Z
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.
Diagnostic ProcedureNBS0003Y
1. INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Ye s > > G O T O 8 .
No >> GO TO 2.
2. CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 53 and ground with CON-
SULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors M72, F102
Fuse block (J/B) connector M4
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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
8 B/P ECM ground[Engine is running]
Idle speedBody ground
123
124B/W
B/RECM ground[Engine is running]
Idle speedBody ground
127
128B
BECM ground[Engine is running]
Idle speedBody ground
Voltage: Battery voltage
PBIB0070E
Page 146 of 720

EC-146
POWER SUPPLY AND GROUND CIRCUIT
Revision: 2006 November2007 350Z
4. CHECK GROUND CONNECTIONS
Models with VDC system, navigation system or telephone
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to EC-150, "
Ground Inspection" .
Models without VDC system, navigation system and telephone
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace ground connections.
5. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 8, 123, 124, 127, 128 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
1. Body ground E17 2. Body ground E43 3. Body ground B102
:Vehicle front
1. Body ground E17 2. Body ground E43 3. Body ground F152
(Passenger side view with dash side
finisher removed)
:Vehicle front
PBIB3560E
PBIB3561E
Continuity should exist.
Page 147 of 720

POWER SUPPLY AND GROUND CIRCUIT
EC-147
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Revision: 2006 November2007 350Z
6. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors M72, F102
Harness connectors F103, B113 (Models with VDC system, navigation system or telephone) or F151
(Models without VDC system, navigation system and telephone)
Harness connectors F3, E12
Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
7. CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector disconnected.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R terminal 17 and ground with
CONSULT-III or tester.
OK or NG
OK >> Go to EC-698, "IGNITION SIGNAL" .
NG >> GO TO 8.
8. CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and then OFF.
3. Check voltage between ECM terminals 125 and ground with
CONSULT-III or tester.
OK or NG
OK >> GO TO 15.
NG (Battery voltage does not exist.)>>GO TO 9.
NG (Battery voltage exists for more than a few seconds.)>>GO TO
12.
9. CHECK ECM POWER SUPPLY CIRCUIT-IV
Check voltage between ECM terminal 24 and ground with CON-
SULT-III or tester.
OK or NG
OK >> GO TO 10.
NG >> GO TO 12.Voltage: Battery voltage
PBIB1915E
Voltage: After turning ignition switch OFF, battery
voltage will exist for a few seconds, then
drop approximately 0V.
PBIB3587E
Voltage: Battery voltage
PBIB3467E
Page 148 of 720

EC-148
POWER SUPPLY AND GROUND CIRCUIT
Revision: 2006 November2007 350Z
10. CHECK ECM POWER SUPPLY CIRCUIT-V
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E7.
3. Check harness continuity between ECM terminals 125 and IPDM E/R terminal 18.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 18.
NG >> GO TO 11.
11 . DETECT MALFUNCTIONING PART
Check the following.
Harness or connectors E108, M15
Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK ECM POWER SUPPLY CIRCUIT-VI
1. Disconnect IPDM E/R harness connector E9.
2. Check harness continuity between ECM terminal 24 and IPDM E/R terminal 46.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 14.
NG >> GO TO 13.
13. DETECT MALFUNCTIONING PART
Check the following.
Harness or connectors E10, F1
Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
14. CHECK 15A FUSE
1. Disconnect 15A fuse from IPDM E/R.
2. Check 15A fuse.
OK or NG
OK >> GO TO 18.
NG >> Replace 15A fuse.Continuity should exist.
Continuity should exist.
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POWER SUPPLY AND GROUND CIRCUIT
EC-149
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Revision: 2006 November2007 350Z
15. CHECK GROUND CONNECTIONS
Models with VDC system, navigation system or telephone
1. Loosen and retighten ground screws on the body. Refer to EC-150, "
Ground Inspection" .
Models without VDC system, navigation system and telephone
1. Loosen and retighten ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 16.
NG >> Repair or replace ground connections.
16. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 8, 123, 124, 127, 128 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 18.
NG >> GO TO 17.
1. Body ground E17 2. Body ground E43 3. Body ground B102
:Vehicle front
1. Body ground E17 2. Body ground E43 3. Body ground F152
(Passenger side view with dash side
finisher removed)
:Vehicle front
PBIB3560E
PBIB3561E
Continuity should exist.
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EC-150
POWER SUPPLY AND GROUND CIRCUIT
Revision: 2006 November2007 350Z
17. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors F103, B113 (Models with VDC system, navigation system or telephone) or F151
(Models without VDC system, navigation system and telephone)
Harness or connectors F3, E12
Harness or connectors M72, F102
Harness for open or short between ECM and ground.
>> Repair open circuit or short to power in harness or connectors.
18. CHECK INTERMITTENT INCIDENT
Refer to 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 open circuit or short to ground or short to power in harness or connectors.
Ground Inspection NBS0003Z
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:
Remove the ground bolt or screw.
Inspect all mating surfaces for tarnish, dirt, rust, etc.
Clean as required to assure good contact.
Reinstall bolt or screw securely.
Inspect for “add-on” accessories which may be interfering with the ground circuit.
If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the
wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one
eyelet make sure no ground wires have excess wire insulation.
For detailed ground distribution information, refer to PG-27, "
Ground Distribution" .
PBIB1870E
Page 151 of 720

DTC U1000, U1001 CAN COMMUNICATION LINE
EC-151
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Revision: 2006 November2007 350Z
DTC U1000, U1001 CAN COMMUNICATION LINEPFP:23710
DescriptionNBS00040
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
On Board Diagnosis LogicNBS006T0
*1: This self-diagnosis has the one trip detection logic.
*2: The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureNBS006T1
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-153, "
Diagnostic Procedure" .
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
U1000*
1
1000*1
CAN communication
line
When ECM is not transmitting or receiving
CAN communication signal of OBD (emission-
related diagnosis) for 2 seconds or more.
Harness or connectors
(CAN communication line is open or
shorted)
U1001*
2
1001*2
When ECM is not transmitting or receiving
CAN communication signal other than OBD
(emission-related diagnosis) for 2 seconds or
more.
Page 152 of 720
EC-152
DTC U1000, U1001 CAN COMMUNICATION LINE
Revision: 2006 November2007 350Z
Wiring DiagramNBS006T2
TBWT1616E