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:
Diagnosis system (TCM)
DIAGNOSIS DESCRIPTION
DIAGNOSIS DESCRIPTION : 1 Trip Detection Diagnosis and 2 Trip Detection
Diagnosis
NOTE:
“Start the engine and turn OFF the ignition switch after warm-up.” This is
defined as 1 trip.
TRIP DETECTION DIAGNOSIS
When initial malfunction is detected, TCM mem ...
Readiness for inspection/maintenance (I/M) test
Due to legal requirements in some states and
Canadian Provinces, your vehicle may be required
to be in what is called the “ready condition”
for an Inspection/Maintenance (I/M) test of
the emission control system.
The vehicle is set to the “ready condition” when it
is driven through c ...
Child safety rear door lock
Child safety locks help prevent the rear doors
from being opened accidentally, especially when
small children are in the vehicle.
The child safety lock levers are located on the
edge of the rear doors.
When the lever is in the unlock position 2 , the
door can be opened from the outside ...