Nissan Sentra Service Manual: B142A Ignition voltage

Description

DTC B142A IGNITION VOLTAGE

Ignition voltage is supplied to the air bag diagnosis sensor unit when the ignition is in the ON position. The air bag diagnosis sensor unit will monitor for low or high ignition voltage.

PART LOCATION

Refer to SRC-5, "Component Parts Location".

DTC Logic

DTC DETECTION LOGIC

With CONSULT

DTC CONFIRMATION PROCEDURE (With CONSULT)

1.CHECK SELF-DIAG RESULT

1. Turn ignition switch ON.
2. Check for DTC using CONSULT.

Is the DTC detected? YES (Current DTC)>>Refer to SRC-96, "Diagnosis Procedure".

YES (Past DTC)>>GO TO 2.

NO >> Inspection End.

2.ERASE SELF-DIAG RESULT

Erase the DTC using CONSULT.

Can the DTC be erased? YES >> Inspection End.

NO >> Refer to SRC-96, "Diagnosis Procedure".

DTC CONFIRMATION PROCEDURE (Without CONSULT)

1.CHECK SELF-DIAG RESULT

1. Turn ignition switch ON.
2. Check the air bag warning lamp status. Refer to SRC-17, "Trouble Diagnosis without CONSULT".

NOTE:

SRS will not enter diagnosis mode if no malfunction is detected in user mode.

Is the DTC detected? YES >> Refer to SRC-96, "Diagnosis Procedure".

NO >> Inspection End.

Diagnosis Procedure

1.HARNESS CONNECTOR

Visually inspect all applicable harness connectors for the following:

• Visible damage to connector or terminal
• Loose terminal
• Poor connection

NOTE:

All harness connectors should be inspected from the air bag diagnosis unit to the end component (including any in-line connectors).

Is the inspection result normal? YES >> GO TO 2.

NO >> Perform one of the following repairs:

• Visible damage: Replace the harness.
• Loose terminal: Secure the terminal.
• Poor connection: Secure the connection.

2.CONFIRM DTC

1. Reconnect all harness connectors.
2. Turn ignition switch ON.
3. Check for DTC using CONSULT.

Is DTC still current? YES >> GO TO 3 NO >> Refer to GI-39, "Intermittent Incident".

3.WIRING HARNESS

Check the wiring harness for visible damage.

NOTE:

The entire wiring harness should be inspected from the air bag diagnosis sensor unit to the end component (including any in-line connectors).

Is the inspection result normal? YES >> GO TO 4.

NO >> Replace the harness.

4.CONFIRM DTC

1. Reconnect all harness connectors.
2. Turn ignition switch ON.
3. Check for DTC using CONSULT.

Is DTC still current? YES >> GO TO 5.

NO >> Refer to GI-39, "Intermittent Incident".

5.AIR BAG DIAGNOSIS SENSOR UNIT

1. Replace the air bag diagnosis sensor unit. Refer to SR-28, "Removal and Installation".

2. Turn ignition switch ON.
3. Check for DTC using CONSULT.

Is DTC still current? YES >> GO TO 6.

NO >> Clear DTC. Inspection End.

6.RELATED HARNESS

Replace the related harness.

>> END

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