Trouble Diagnosis Summary of NVIS

ECM INT CIRC-IMMU

System Description
NVIS (Nissan Vehicle Immobilizer System - NATS) will immobilize the engine if someone tries to start it without the registered key of NVIS (NATS). Only NVIS (NATS) ignition keys with ID numbers that have been registered into the ECM and the IMMU allow the engine to run.
A malfunction that triggers this code may turn the security indicator ON to make the engine hard to start. If the security indicator illuminates with the ignition key ON or the engine running, it may indicate that there is an abnormality in the system. For this condition perform SELF DIAGNOSIS.
It is normal for the security indicator to blink when the ignition switch is in OFF or ACC.
NVIS (NATS) trouble diagnoses, system initialization and additional registration of other NVIS (NATS) ignition key IDs must be carried out using CONSULT-II hardware and CONSULT-II NVIS (NATS) software.

On Board Diagnostic Logic
The malfunction of ECM internal circuit of IMMU communication line is detected.

Possible Cause
- ECM

Diagnostic Repair Procedure (for confirmed incidents)
1. ECM component test: Perform steps a to c
a. Confirm SELF DIAGNOSIS "ECM INT CIRC-IMMU" displayed on CONSULT-II screen.(See Part B).
b. Replace ECM

c. Perform initialization with CONSULT-II.

Diagnostic Repair Procedure (for unconfirmed incidents)
1. Run engine; select SELF DIAGNOSIS with CONSULT-II; perform "Wiggle Test" on all related connectors.
2. Inspect all related harnesses, connectors and pins.

CHAIN OF ECM-IMMU

System Description
NVIS (Nissan Vehicle Immobilizer System - NATS) will immobilize the engine if someone tries to start it without the registered key of NVIS (NATS). Only NVIS (NATS) ignition keys with ID numbers that have been registered into the ECM and the IMMU allow the engine to run.
A malfunction that triggers this code may turn the security indicator ON to make the engine hard to start. If the security indicator illuminates with the ignition key ON or the engine running, it may indicate that there is an abnormality in the system. For this condition perform SELF DIAGNOSIS.
It is normal for the security indicator to blink when the ignition switch is in OFF or ACC.
NVIS (NATS) trouble diagnoses, system initialization and additional registration of other NVIS (NATS) ignition key IDs must be carried out using CONSULT-II hardware and CONSULT-II NVIS (NATS) software.

On Board Diagnostic Logic
Communication impossible between ECM and IMMU

Possible Cause
- Open circuit in battery voltage line, ignition line or ground line of IMMU circuit.
- Open circuit in the communication line between IMMU and ECM.
- Short circuit in the IMMU/ECM communication line to battery voltage line and/or ground line.
- The IMMU is malfunctioning.
- The ECM is malfunctioning.

Diagnostic Repair Procedure (for confirmed incidents)
1. Check power supply and ground for IMM U.
2. Check communication line between ECM and IMMU:
Disconnected, ignition key ON, Continuity/No shorts to ground or power

3. Check ECM communication interface:
Connect ECM connector, disconnect IMMU connector, use CONSULT-II, select SELF-FUNCTION CHECK, touch START.
ECM checks communication interface.
- If NG is displayed, replace ECM (see part B). Then perform initialization with CONSULT-II.
- If OK is displayed, replace IMMU (see part A). Then perform initialization with CONSULT-II.

Diagnostic Repair Procedure (for unconfirmed incidents)
1. Run engine; select SELF DIAGNOSIS with CONSULT-II; perform "Wiggle Test" on all related connectors.
2. Inspect all related harnesses, connectors and pins.

DIFFERENCE OF KEY

System Description
NVIS (Nissan Vehicle Immobilizer System - NATS) will immobilize the engine if someone tries to start it without the registered key of NVIS (NATS). Only NVIS (NATS) ignition keys with ID numbers that have been registered into the ECM and the IMMU allow the engine to run.
A malfunction that triggers this code may turn the security indicator ON to make the engine hard to start. If the security indicator illuminates with the ignition key ON or the engine running, it may indicate that there is an abnormality in the system. For this condition perform SELF DIAGNOSIS.
It is normal for the security indicator to blink when the ignition switch is in OFF or ACC.
NVIS (NATS) trouble diagnoses, system initialization and additional registration of other NVIS (NATS) ignition key IDs must be carried out using CONSULT-II hardware and CONSULT-II NVIS (NATS) software.

On Board Diagnostic Logic
IMMU can receive the key ID signal but the result of ID verification between key ID and IMMU is NG.

Possible Cause
- Unregistered key
- IMMU

Diagnostic Repair Procedure (for confirmed incidents)
1. Check NVIS (NATS) ignition key ID chip:
Attempt to start the engine with any of the other registered NVIS (NATS) ignition keys.
If the engine starts, replace non-functional key and perform initialization with CONSULT-II. Reregister all NVIS (NATS) ignition key IDs.
2. Check IMMU installation.
If IMMU installation is OK, IMMU is malfunctioning. Perform steps a and b.
a. Replace IMMU (refer to part A in illustration).
b. Perform initialization.

ID DISCORD, IMM-ECM

System Description
NVIS (Nissan Vehicle Immobilizer System - NATS) will immobilize the engine it someone tries to start it without the registered key of NVIS (NATS). Only NVIS (NATS) ignition keys with ID numbers that have been registered into the ECM and the IMMU allow the engine to run.
A malfunction that triggers this code may turn the security indicator ON to make the engine hard to start. If the security indicator illuminates with the ignition key ON or the engine running, it may indicate that there is an abnormality in the system. For this condition perform SELF DIAGNOSIS.
It is normal for the security indicator to blink when the ignition switch is in OFF or ACC.
NVIS (NATS) trouble diagnoses, system initialization and additional registration of other NVIS (NATS) ignition key IDs must be carried out using CONSULT-II hardware and CONSULT-II NVIS (NATS) software.

On Board Diagnostic Logic
The result of ID verification between IMMU and ECM is NG. System initialization is required.

Possible Cause
- System initialization has not yet been completed.
- ECM

Diagnostic Repair Procedure (for confirmed incidents)
1. Perform initialization with CONSULT-II and re-register all NVIS (NATS) ignition key IDs.
2. If initialization is not completed or fails, CONSULT-II displays INITIALIZATION FAIL. ECM is malfunctioning. Perform steps a and b.
a. Replace IMMU (refer to part F in illustration).
b. Re-perform initialization.

Diagnostic Repair Procedure (for unconfirmed incidents)
1. Run engine, select SELF DIAGNOSIS with CONSULT-II, perform "Wiggle Test" on all related connectors.
2. Inspect all related harnesses, connectors and pins.

DON'T ERASE BEFORE CHECKING ENG DIAG

System Description
NVIS (Nissan Vehicle Immobilizer System - NATS) will immobilize the engine if someone tries to start it without the registered key of NVIS (NATS). Only NVIS (NATS) ignition keys with ID numbers that have been registered into the ECM and the IMMU allow the engine to run.
A malfunction that triggers this code may turn the security indicator ON to make the engine hard to start. If the security indicator illuminates with the ignition key ON or the engine running, it may indicate that there is an abnormality in the system. For this condition perform SELF DIAGNOSIS.
It is normal for the security indicator to blink when the ignition switch is in OFF or ACC.
NVIS (NATS) trouble diagnoses, system initialization and additional registration of other NVIS (NATS) ignition key IDs must be carried out using CONSULT-II hardware and CONSULT-II NVIS (NATS) software.

On Board Diagnostic Logic
All engine trouble codes except NATS trouble code have been detected in ECM.

Possible Cause
- All engine trouble codes except NVIS (NATS) trouble code have been detected in ECM.

Diagnostic Repair Procedure
1. Perform SELF DIAGNOSIS with CONSULT-II and print the codes displayed.
2. Turn ignition switch OFF.
3. If any NVIS (NATS) trouble codes were displayed along with "DON'T ERASE BEFORE CHECKING ENG DIAG", repair NVIS (NATS) malfunction. If necessary, perform SELF FUNCTION CHECK or C/U INITIALIZATION with CONSULT-II.

NOTE: Do not erase NVIS (NATS) SELF-DIAGNOSIS results at this time.

4. Check ENGINE SELF DIAGNOSIS results with CONSULT-II using CONSULT-II generic program card.
- If there are codes other than NATS MALFUNCTION displayed, repair engine system according to those codes.
- If only NATS MALFUNCTION is displayed, erase engine SELF DIAGNOSIS results.
5. Start engine.
- If engine does not start a malfunction may still exist with NVIS (NATS). Recheck NVIS (NATS) SELF DIAGNOSIS results and repair any codes displayed.
6. Erase NVIS (NATS) SELF DIAGNOSIS results with CONSULT-II using NVIS (NATS) program card. And, if it has not been done already, erase ENGINE SELF DIAGNOSIS results with CONSULT-II using the generic program card. With engine running, verify that no codes return or are displayed.
- If any codes will not erase from ENGINE SELF DIAGNOSIS results, repair as needed.

LOCK MODE

System Description
NVIS (Nissan Vehicle Immobilizer System - NATS) will immobilize the engine if someone tries to start it without the registered key of NVIS (NATS). Only NVIS (NATS) ignition keys with ID numbers that have been registered into the ECM and the IMMU allow the engine to run.
A malfunction that triggers this code may turn the security indicator ON to make the engine hard to start. If the security indicator illuminates with the ignition key ON or the engine running, it may indicate that there is an abnormality in the system. For this condition perform SELF DIAGNOSIS.
It is normal for the security indicator to blink when the ignition switch is in OFF or ACC.
NVIS (NATS) trouble diagnoses, system initialization and additional registration of other NVIS (NATS) ignition key IDs must be carried out using CONSULT-II hardware and CONSULT-II NVIS (NATS) software.

On Board Diagnostic Logic
When the starting operation is carried out five or more times consecutively under the following conditions, NVIS
(NATS) will shift the mode to one which prevents the engine from being started.
- Unregistered ignition key is used
- IMMU or ECM malfunction

Possible Cause
- Use of unregistered ignition key
- Malfunctioning ignition key
- IMMU
- ECM

Diagnostic Repair Procedure
1. Perform SELF DIAGNOSIS results with CONSULT-II. Confirm LOCK MODE is displayed on CONSULT-II screen.
2. Escape from LOCK MODE: Perform steps a to e.
a. Turn ignition switch OFF.
b. Turn ignition switch ON with registered key. (Do not start engine.) Wait 5 seconds.
c. Return the key to OFF position.
d. Repeat steps 2 and 3.
e. Start engine. If engine start, system is escaped from LOCK MODE.
3. If engine cannot start in step 2, check IMMU installation.
4. Perform initialization with CONSULT-II and re-register all NVIS (NATS) ignition key IDs.
5. If initialization is not completed or fails, CONSULT-II displays INITIALIZATION FAIL: Perform steps a-b.
a. Check NVIS (NATS) ignition key ID chip:
Attempt to start the engine with any of the other registered NVIS (NATS) ignition keys. If the engine starts, replace non-functional key and perform initialization with CONSULT-II. Reregister all NVIS (NATS) ignition key IDs.
b. Check IMMU installation.
6. If IMMU installation is OK, IMMU is malfunctioning. Perform the following.
a. Replace IMMU.
b. Perform initialization.