Nissan Altima L32. Manual - part 250
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-121
< FUNCTION DIAGNOSIS >
[QR25DE FOR CALIFORNIA]
C
D
E
F
G
H
I
J
K
L
M
A
EC
N
P
O
4. Fully release the accelerator pedal.
ECM has entered to Diagnostic Test Mode II (Self-diagnostic results).
NOTE:
Wait until the same DTC (or 1st trip DTC) appears to confirm all DTCs certainly.
HOW TO ERASE DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS)
1. Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to “HOW TO SET DIAGNOSTIC TEST
MODE II (SELF-DIAGNOSTIC RESULTS)”.
2. Fully depress the accelerator pedal and keep it for more than 10 seconds.
The emission-related diagnostic information has been erased from the backup memory in the ECM.
3. Fully release the accelerator pedal, and confirm the DTC 0000 is displayed.
OBD System Operation Chart
Relationship Between MIL, 1st Trip DTC, DTC and Detectable Items
• When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.
• When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MIL will come on.
• The MIL will go off after the vehicle is driven 3 times (driving pattern B) with no malfunction. The drive is
counted only when the recorded driving pattern is met (as stored in the ECM). If another malfunction occurs
while counting, the counter will reset.
• The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A) with-
out the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and Fuel Injec-
tion System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times (driving pattern
C) without the same malfunction recurring. The “TIME” in “SELF-DIAGNOSTIC RESULTS” mode of CON-
SULT-III will count the number of times the vehicle is driven.
• The 1st trip DTC is not displayed when the self-diagnosis results in OK for the 2nd trip.
Summary Chart
For details about patterns B and C under “Fuel Injection System” and “Misfire”, see “EXPLANATION FOR DRIVING PATTERNS FOR
“MISFIRE <EXHAUST QUALITY DETERIORATION>”, “FUEL INJECTION SYSTEM”.
For details about patterns A and B under Other, see “EXPLANATION FOR DRIVING PATTERNS FOR “MISFIRE <EXHAUST QUALITY
DETERIORATION>”, “FUEL INJECTION SYSTEM”.
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.
Relationship Between MIL, DTC, 1st Trip DTC and Driving Patterns for “Misfire <Exhaust Quality Deterioration>”,
“Fuel Injection System”
PBIB0092E
Items
Fuel Injection System
Misfire
Other
MIL (goes off)
3 (pattern B)
3 (pattern B)
3 (pattern B)
DTC, Freeze Frame Data (no
display)
80 (pattern C)
80 (pattern C)
40 (pattern A)
1st Trip DTC (clear)
1 (pattern C), *
1
1 (pattern C), *
1
1 (pattern B)
1st Trip Freeze Frame Data
(clear)
*1, *2
*1, *2
1 (pattern B)