One or Two Trip Detection Logic of OBD-II
ONE TRIP DETECTION LOGICIf a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC (diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. - First Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive, the MIL will illuminate. - Second Trip.
A/T-related parts for which the MIL illuminates during the first or second test drive are listed in the table.
The "trip" in the "One or Two Trip Detection logic"' means a driving mode in which self-diagnosis is performed during vehicle operation.
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
Without Scan Tools
1. The number of blinks of the malfunction indicator lamp in the Diagnostic Test Mode II (Self-Diagnostic Results) Examples: 1101, 1102, 1103, 1104, etc.
These DTCs are controlled by NISSAN.
With Consult
2. CONSULT or GST (Generic Scan Tool) Examples: P0705, P0710, P0720, P0725, etc. These DTCs are prescribed by SAE J2012.
With Generic Scan Tools
(CONSULT also displays the malfunctioning component or system.)
- 1st trip DTC No. is the same as DTC No.
- Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. However, in case of the Mode II and GST they do not indicate whether the malfunction is still occurring or occurred in the past and returned to normal.
CONSULT can identify them as shown below. Therefore, using CONSULT (if available) is recommended.
A sample of CONSULT display for DTC is shown in the image. DTC or 1st trip DTC of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode for "ENGINE" with CONSULT. Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be "0".
If a 1st trip DTC is stored in the ECM, the time data will be "[1t]".