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
Precautions for Trouble Diagnosis
Caution:
Follow the instructions listed below. Failure to do this may cause
damage to parts:
Never apply 7.0 V or more to the measurement terminal.
Use a tester with open terminal voltage of 7.0 V or less.
Turn the ignition switch off and disconnect the ...
Can communication circuit
Diagnosis procedure
1.Connector inspection
Turn the ignition switch OFF.
Disconnect the battery cable from the negative terminal.
Disconnect all the unit connectors on can communication system.
Check terminals and connectors for damage, bend and loose connection.
Is the inspection resu ...
P0444, P0445 EVAP Canister purge volume control solenoid valve
DTC Logic
DTC DETECTION LOGIC
DTC No.
CONSULT screen terms
(Trouble diagnosis content)
DTC detecting condition
Possible cause
P0444
PURG VOLUME CONT/V
(Evaporative emission system
purge control valve circuit open)
An excessively low voltage signal is sent to ...
