on Saturday I changed the oil in my car, and checked the air filter. I did everything normal, added 4 quarts of oil, put the air filter back cuz it looked clean. The car seems to be running finie, I have enough oil according to the dip stick. Temp in normal, and the engine sounds smoother than it did before, so why is the check engine light on????? any help would be awesome. Oh, its a 95 pathfinder, 2 wheel drive XE.
Try running the self diagnostic to see why the check engine light is on. Here's how you do it:
Mode I - Exhaust Oxygen Sensor Monitor
Use Mode I to determine if the Oxygen Sensor is functioning properly.
Warm the engine to normal temperature.
Run the engine above 2000 RPM under no load while looking at the ECU.
Make sure the GREEN LED goes on and off more than five times during ten seconds at 2000 RPM.
If the number of flashes are not more than five, replace the oxygen sensor. If the LED does not flash, check the sensor's circuit.
Mode II - Mixture Ratio Control Monitor
Use Mode II to determine if the air/fuel mixture is cycling correctly.
Warm the engine to normal operating temperature.
Turn the dial on the ECU fully clockwise (or if you have a switch, turn it on).
After the LED flashes twice, turn the dial fully counter clockwise (or turn the switch off).
Run the engine above 2000 RPM under no load while looking at the ECU.
If the RED LED blinks simultaneously with the GREEN LED, the air/fuel mixture is cycling properly.
If the RED LED stays off, the mixture is more than 5% rich.
If the RED LED stays on, the mixture is more than 5% lean.
If the RED LED stays on or off above 2000 RPM, complete the diagnostics before beginning repairs.
Mode III - Stored Fault Code Reporting
Use Mode III to retrive all stored trouble codes in memory.
Turn the ignition switch on, but do not start the engine.
On the ECU, turn the diagnostic mode selector screw fully clockwise (or if you have a switch, turn it on). Wait until the LED flashes 3 quick bursts, then turn the screw fully counter clockwise (or turn the switch off).
The check engine light will begin to flash trouble codes. Red flashes are units of ten and green flashes are units of one. (red-3 flashes, green-1 flash = code 31) Note all codes until it begins to loop.
To clear all stored codes, turn the screw fully clockwise (or turn the switch on). Wait until the LED flashes 4 quick bursts, then turn the screw fully counter clockwise (or turn the switch off). To retain the codes in memory, simply turn the ignition off.
KA24E Codes:
11 Crankshaft Position Sensor Circuit
12 Mass Air Flow Sensor Circuit
13 Engine Coolant Temperature Sensor Circuit
14 Vehicle Speed Sensor Circuit
21 Ignition Signal Missing in Primary Coil
31 Engine Control Unit (ECU)
33 Oxygen Sensor Circuit
41 Air Temperature Sensor Circuit
43 Throttle Position Sensor Circuit
55 No Malfunctions
Complete list of Codes for other models:
11 Crank Angle Sensor/Camshaft Position Sensor
12 Air Flow Meter/Mass Air Flow Sensor
13 Engine Coolant Temperature Sensor
14 Vehicle Speed Sensor
21 Ignition Signal
22 Fuel Pump
23 Idle Switch
24 Throttle Valve Switch
25 Idle Speed Control Valve
28 Cooling Fan Circuit
31 ECU
32 EGR Function
33 Heated Oxygen Sensor
34 Knock Sensor
35 Exhaust Gas Temperature Sensor
36 EGR Control-Back Pressure Transducer
37 Knock Sensor
38 Right hand bank Closed Loop (B2)
41 Intake Air Temperature Sensor
42 Fuel Temperature Sensor
43 Throttle Position Sensor
45 Injector Leak
47 Crankshaft Position Sensor
51 Injector Circuit
53 Oxygen Sensor
54 A/T Control
55 No Malfunction
63 No. 6 Cylinder Misfire
64 No. 5 Cylinder Misfire
65 No. 4 Cylinder Misfire
66 No. 3 Cylinder Misfire
67 No. 2 Cylinder Misfire
68 No. 1 Cylinder Misfire
71 Random Misfire
72 TWC Function right hand bank
73 TWC Function right hand bank
76 Fuel Injection System Function right hand bank
77 Rear Heated Oxygen Sensor Circuit
82 Crankshaft Position Sensor
84 A/T Diagnosis Communication Line
85 VTC Solenoid Valve Circuit
86 Fuel Injection System Function right hand bank
87 Canister Control Solenoid Valve Circuit
91 Front Heated Oxygen Sensor Heater Circuit right hand bank
94 TCC Solenoid Valve
95 Crankshaft Position Sensor
98 Engine Coolant Temperature Sensor
101 Front Heated Oxygen Sensor Heater Circuit right hand bank
103 Park/Neutral Position Switch Circuit
105 EGR and EGR Canister Control Solenoid Valve Circuit
108 Canister Purge Control Valve Circuit
Check or replace the sensor(s) and related components corresponding the list of stores trouble codes.
Mode IV - Switch Operation Monitor
Use Mode IV to determine if the Throttle Position Sensor (TPS), Starter circuit and/or Vehicle Speed Sensor (VSS) are in proper working order.
Turn the ignition switch on, but do not start the engine.
Turn the dial on the ECU fully clockwise. After the LED flashes 4 times, turn the dial fully counter clockwise.
Make sure the RED LED is turned off.
Make sure the RED LED turns on when depressing the gas pedal. If not, check or replace the Throttle Position Sensor.
Make sure the RED LED turns on when turning the ignition key the START position. If not, check or replace the starter.
Drive the vehicle with the ECU unbolted and within view. Make sure the GREEN LED turns on when speed is 12 MPH or more. If not, check or replace the Vehicle Speed Sensor.
Mode V - Real Time Diagnostic Function
Use Mode V to determine if the Crankshaft Position Sensor (CPS), Mass Air Flow (MAF) sensor and/or Ignition signal are working properly.
Start engine.
Turn the dial on the ECU fully clockwise.
After the LED flashes 5 times, turn the dial fully counter clockwise.
Make sure LEDs do not flash for 5 minutes when racing or idling the engine.
If it flashes, count the number of flashes, turn engine off, and see the following 3 paragraphs.
Perform real-time diagnosis insepction and repair or replace malfunctioning part if present.
If LEDs do not flash for 5 minutes, turn engine off.
If the RED LED flashes 3 times for 1.5 seconds, check the Crankshaft Position Sensor. Check the harness continuity at CPS when the engine is stopped. Inspect the harness for dust and clean if necessary. Check the pin terminal at ECU for bends and remove them as necessary. Reconnect harness and recheck continuity. During real-time diagnosis, tap the harness connector or component and check if trouble code is displayed. If so, replace terminal.
If the GREEN LED flashes twice-3 times for 0.5 seconds, check Mass Air Flow Sensor. Check the harness continuity at MAF when the engine is stopped. Inspect the harness for dust and clean if necessary. Check the pin terminal at ECU for bends and remove them as necessary. Reconnect harness and recheck continuity. During real-time diagnosis, tap the harness connector or component and check if trouble code is displayed. If so, replace terminal.
If the GREEN LED flashes 4 times for 0.2 seconds 3 times, check the ignition signal. Check the harness continuity when the engine is stopped. Inspect the harness for dust and clean if necessary. Check the pin terminal at ECU for bends and remove them as necessary. Reconnect harness and recheck continuity. During real-time diagnosis, tap the harness connector or component and check if trouble code is displayed. If so, replace terminal.
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95 WD-21 DVD/TV system-otherwise stock kid hauler
95 D-21 KC XE 3" lift- built for rockcrawlin!
Last edited by Tolleyy : Feb 10th, 2003 at 06:42 PM.
Is there a way to sticky the info I posted above? A lot of people here seem to have wierd idle or check engine light problems and the first thing you need to do is run the self diagnostic as described in my first post.
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95 WD-21 DVD/TV system-otherwise stock kid hauler
95 D-21 KC XE 3" lift- built for rockcrawlin!
yes thanks for the very detailed post on the self diagnostic...let me try to puxxle you again. So Im driveing home and the light goes off, whats that all about...but there has been an odd smell coming from the car like its running super rich. any thoughts my friend says I have a bad MAF sensor. what do you guru's think?
Not a ssan but I had a dodge stratus do the same thing it was the oxygen sensor. My sisters light came on in her jetta samething, yep o2 sensor. Oh yea on my last truck (93 nissan) I had the cat replaced to pass smog and a bit later the check engine light keep comeing on and going off, you guessed it. the o2 sensor. I sold the truck before I repaired it, but I told the guy the problem and hes been driving it for a year now. Damb i would guess that truck has close to 170,000 on it. Had 150,000 when i sold it. Sorry kinda went off there.
Even if the light comes on and off, the computer stores the codes from the last 50 key turns. Run the diagnostic and get the code. it will tell you if it's the MAF or the 02 sensor, but my moneys on the 02
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95 WD-21 DVD/TV system-otherwise stock kid hauler
95 D-21 KC XE 3" lift- built for rockcrawlin!
i also have that kind of problem. it shows that i have code 1605 (A/T Diagnosis Communication Line)
it's started when this tire installer check my fog light wiring.....suddenly my defagger at the back did not work also and this service engine is now lighting!
Does any one know if Nissan is aware of some of these issues.
I have 2002 Altima and have been told of antifreeze leaking into the engine which seems to cause a slight shimmy when starting and I've been told that the car smells funny when I drive off.
Does any one have this issue?
This info is ALREADY stickied at the top of the forum...do a little searching, people.
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Owner of NPORA, mod for Nissan-Infiniti Forums, NissanForums.com, NissanHelp.com, AllNissans.com and VGPowered Forums
'88 Pathfinder: 6" of lift, 33x13.50 Swamper LTB's, Rancho 9000's, L&P Stage 3 steering system, K&N, Pacesetter headers and 2.5" exhaust, Lock-Right locker, 110A alty and electric fan swap, dual batteries, 700W+ worth of PIAAs, etc.
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