Nissan Sentra Service Manual: On Board Diagnostic (OBD) System of Engine and CVT
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the driver of a malfunction causing emission deterioration.
CAUTION:
- Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc. will cause the MIL to light up.
- Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease, dirt, bent terminals, etc.)
- Certain systems and components, especially those related to OBD, may use a new style slide-locking type harness connector. For description and how to disconnect, refer to PG-42, "Description".
- Be sure to route and secure the harnesses properly after work. The interference of the harness with a bracket, etc. may cause the MIL to light up due to the short circuit.
- Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system, etc.
- Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and TCM (Transmission control module) before returning the vehicle to the customer.
Precaution for Procedure without Cowl Top Cove.r.
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc to prevent damage to
windshield.
...
General Precautions
Always use a 12 volt battery as power source.
Do not attempt to disconnect battery cables while engine is
running.
Before connecting or disconnecting the ECM harness connector,
turn ignitio ...
Other materials:
Precaution
Precaution for supplemental restraint system (srs) "air bag" and "seat belt
pre-tensioner"
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT
PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injur ...
P0456 EVAP Control system
DTC Logic
DTC DETECTION LOGIC
This diagnosis detects leaks in the EVAP line between fuel tank and EVAP
canister purge volume control solenoid
valve, using the negative pressure caused by decrease of fuel temperature in the
fuel tank after turning
ignition switch OFF.
If ECM judges there a ...
Does not stop fully-open or fullyclosed
position
Diagnosis procedure
1. Perform initialization procedure
Perform initialization procedure.
Refer to RF-18, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair
Requirement".
Is the inspection result normal?
YES >> Inspection End.
NO >> Perform basic ins ...
