Nissan Sentra Service Manual: Diagnosis description : permanent diagnostic trouble code (permanent DTC)
Permanent DTC is defined in SAE J1979/ISO 15031-5 Service $0A.
ECM stores a DTC issuing a command of turning on MIL as a permanent DTC and keeps storing the DTC as a permanent DTC until ECM judges that there is no presence of malfunction.
Permanent DTCs cannot be erased by using the erase function of CONSULT or Generic Scan Tool (GST) and by disconnecting the battery to shut off power to ECM. This prevents a vehicle from passing the in-use inspection without repairing a malfunctioning part.
When not passing the in-use inspection due to more than one permanent DTC, permanent DTCs should be erased, referring to this manual.
NOTE:
- The important items in in-use inspection are that MIL is not ON, SRT test items are set, and permanent DTCs are not included.
- Permanent DTCs do not apply for regions that permanent DTCs are not regulated by law.
PERMANENT DTC SET TIMING
The setting timing of permanent DTC is stored in ECM with the lighting of MIL when a DTC is confirmed.
Diagnosis description : system readiness
test (SRT) code
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979/ISO
15031-5.
As part of an enhanced emissions test for Inspection & Maintenance (I/M),
certain states require the s ...
Diagnosis description : malfunction indicator lamp (MIL)
When emission-related ECU detects a malfunction in the emission
control systems components and/or the powertrain control components
(which affect vehicle emissions), it turns on/blinks MIL to
infor ...
Other materials:
P0127 IATSensor
DTC Logic
DTC DETECTION LOGIC
DTC No.
CONSULT screen terms
(Trouble diagnosis content)
DTC detecting condition
Possible cause
P0127
IAT SENSOR-B1
(Intake air temperature too high)
Rationally incorrect voltage from the sensor is
sent to ECM, compared with the ...
Symptom diagnosis
Squeak and rattle trouble diagnoses
Work Flow
CUSTOMER INTERVIEW
Interview the customer if possible, to determine the conditions that exist
when the noise occurs. Use the Diagnostic
Worksheet during the interview to document the facts and conditions when the
noise occurs and any
custome ...
Operating tips
When the engine coolant temperature and
outside air temperature are low, the air flow
from the foot outlets may not operate for a
maximum of 150 seconds. However, this is
not a malfunction. After the coolant temperature
warms up, air flow from the foot outlets
will operate normally.
...
