bill99gxe

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Much thanks to Daniel B. Martin for this info and his efforts.

First, Diagnostic Trouble Codes may be found on-line at:
http://web2.airmail.net/scutchen/ma...q/engcodes1.gif
http://web2.airmail.net/scutchen/ma...q/engcodes2.gif

bill99gxe

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Diagnostic Trouble Code 0102 points to a problem with the Mass Air Flow Sensor. The MAFS is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a thin film that is supplied with electric current from the Engine Control Module. The temperature of the hot film is controlled by the ECM a certain amount. The heat generated by the hot wire is reduced as the intake air flows around it. The more air, the greater the heat loss. Therefore, the ECM must supply more electric current to the hot film as air flow increases. This maintains the temperature of the hot film. The ECM detects the air flow by means of this current change.

This malfunction is detected when an out-of-range voltage is sent to the ECM. That voltage might be too high or too low.

a) An excessively high voltage from the MAFS is sent when the engine is not running.
b) An excessively high voltage from the MAFS is sent under light load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Faulty MAFS

c) An excessively low voltage from the MAFS is sent when the engine is not running.
d) An excessively low voltage from the MAFS is sent under heavy load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Intake air leaks
- Faulty MAFS

With DTC 0102 the ECM is supposed to switch into Fail Safe mode and limit engine speed to 2400 rpm.

bill99gxe

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Diagnostic Trouble Code 0103 points to the Engine Coolant Temperature Sensor. The factory service manual says this DTC is set when the ECTS signal has an excessively high or low voltage. It suggests testing the ECTS and also the associated electric connector and wiring harness.

On the 4th Generation Maxima engine the Engine Coolant Temperature Sensor is located in the water outlet tube close to the engine end of the upper radiator hose. There are two sensors in that area. The one nearest the hose is for the dashboard temperature gauge. The ECTS, the one you're interested in, is right next to the the gauge sending unit. There is a good picture of these sensors in the Haynes manual on page 3-7.

With the engine cold, disconnect the ECTS and measure its resistance. Reconnect the ECTS, start the engine, run it until fully warmed up. Stop the engine, and repeat the resistance measurement. The "warm" reading should be a much lower value than the "cold" reading.

The specs for the ECTS are:
Engine coolant temperature 68F, ECTS resistance 2.1 - 2.9 Kohms
Engine coolant temperature 194F, ECTS resistance 0.24 - 0.26 Kohms
(Roughly a factor of ten difference.)

bill99gxe

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Diagnostic Trouble Code 0104 points to a problem with the Vehicle Speed Sensor or the associated wiring.

The Vehicle Speed Sensor installed on the transaxle. The part inside the transaxle has a plastic gear which is driven by the internal parts of the transaxle. The part outside is a signal generator which produces a square wave of amplitude 5.2 volts and frequency proportional to vehicle speed.

Remove the VSS, attach a voltmeter to the electric leads, and spin the gear
by hand. If you get zero volts, it's dead.

One owner discovered his VSS was not fully seated in the transaxle. He just tapped it inward, and retightened the 10mm mounting bolt.

For more information please refer to the Chilton repair manual (page 4-22) or the Haynes repair manual (page 6-16).

bill99gxe

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Diagnostic Trouble Code 0111 is detected when ...
- EVAP control system does not operate properly.
- EVAP control system has a leak in the line between intake manifold and EVAP control system pressure sensor.

Possible causes include ...
- EVAP canister purge volume control solenoid valve stuck closed.
- EVAP control system pressure sensor and its circuit.
- Loose, disconnected, or improper connection of rubber tube.
- Blocked rubber tube.
- Blocked or bent rubber tube to MAP/BARO switch solenoid valve.
- Cracked EVAP canister.
- EVAP canister purge volume control solenoid valve.
- Closed Throttle Position Switch.
- Improper connection of one-way valve.
- Blocked purge port.
- EVAP canister vent control valve.

This is a "jackpot" code. It points to so many possible causes as to be almost useless. It may be accompanied by another DTC which is more specific.

bill99gxe

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Diagnostic Trouble Code 0115 indicates a problem with the fuel management system on the right cylinder bank. The right bank is also called the rear bank. It is cylinders 1,3,5.

The Front Heated Oxygen Sensor for the right bank sent signals to the Engine Control Module indicating an excessively lean fuel mixture. The ECM attempted to correct this problem by directing the fuel injectors to supply more gasoline. Further signals from the Oxygen Sensor indicate that the attempt to correct the lean mixture condition was unsuccessful, and the fuel mixture continues to be too lean.

Possible causes include ...
- Intake air leaks
- Defective Front Heated Oxygen Sensor
- Fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow Sensor

bill99gxe

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Diagnostic Trouble Code 0201 indicates a problem with the ignition coil and power transistor. The ignition signal from the Engine Control Module is sent to and amplified by the power transistor. The power transistor turns on and off the ignition coil primary circuit. This on-off operation induces the proper high voltage in the coil secondary circuit.

The malfunction is detected when the ignition signal in the primary circuit is not entered during engine cranking or running.

The items to check include
- Harness or connectors (the ignition primary circuit is open or shorted.)
- Power transistor unit built into ignition coil
- Condenser
- Crankshaft Position Sensor (REF)
- Crankshaft Position Sensor (REF) circuit

A misfire on any individual cylinder should set a code, and a problem with the CPS should also set a code.

I would have expected to see DTC 0201 along with one of the following DTCs.
0407 - Crankshaft Position Sensor (REF)
0608 - Cylinder 1 misfire
0607 - Cylinder 2 misfire
0606 - Cylinder 3 misfire
0605 - Cylinder 4 misfire
0604 - Cylinder 5 misfire
0603 - Cylinder 6 misfire

You didn't get one of these "companion" DTCs, and that is puzzling. Maybe one of them will show up in the next few days.

bill99gxe

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Diagnostic Trouble Code 0210 points to a problem with the fuel injection system. When the engine management system is running in closed-loop mode the Engine Control Unit (the computer) makes continual adjustments to maintain the air-fuel ratio near the ideal point. To achieve this it relies on signals from many sensors including the Mass Air Flow Sensor and the Oxygen Sensors.

This malfunction is detected when the ECM finds that it cannot properly control the air/fuel mixture, and the mixture is too lean (too much air). DTC 0210 indicates this problem exists on the left bank (the front bank, cylinders 2, 4, and 6). Possible causes include ...
- Intake air leaks
- Front Oxygen Sensor
- one or more fuel injectors on the front bank
- exhaust gas leaks
- incorrect fuel pressure
- lack of fuel
- Mass Air Flow Sensor

bill99gxe

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Diagnostic Trouble Code 0302 points to a problem with the Exhaust Gas Recirculation system. The malfunction is detected by the Engine Control Module when no EGR flow is detected under conditions which call for EGR. Possible causes include:
- The electrical harness or connectors (valve circuit open or shorted)
- The EGR valve is stuck closed
- Weak or dead battery
- The EGR passage is clogged
- Faulty EGR temperature sensor circuit
- A leak somewhere in the exhaust system

The EGR Volume Control Valve may be tested with an ohmmeter. Disconnect the electrical connector. Looking at the connector half which is attached to the EGRVCV with the latch at the 12 o'clock position you will see two rows of three terminals. The top row is numbered 1-3, right to left. The bottom row is numbered 4-6, right to left. Measure the resistance between these terminal pairs:
2 1
2 3
5 4
5 6
... all resistance values should be 20.9-23.1 ohms at 68 degrees F.

Reconnect the EGRVCV connector halves. Turn the ignition switch ON OFF repeatedly. Verify that the EGRVCV shaft moves smoothly forward backward according to the ignition switch position.

The Exhaust Gas Temperature Sensor may be tested with an ohmmeter. The specifications are ...
- at 32 degrees F, 0.68-1.11 Megohms
- at 122 degrees F, 0.09-0.12 Megohms
- at 212 degrees F, 0.017-0.024 Megohms

bill99gxe

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Diagnostic Trouble Code 0303 indicates a problem with the front Oxygen Sensor on the left cylinder bank. The left bank is also called the front bank. It is cylinders 2,4,6. A normal signal sweeps back and forth between 0.2 volts and 0.8 volts. This malfunction was detected when the Engine Control Module received a signal from the sensor which was a constant value of approximately 0.3 volts.

Possible causes include ...
- Harness or connectors (the sensor circuit is open or shorted).
- Defective Oxygen Sensor

bill99gxe

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Diagnostic Trouble Code 0304 points to a problem with the Knock Sensor. The KS is attached to the cylinder block. It senses engine knocking using a piezoelectric element. A knocking vibration from the cylinder block is senses as vibrational pressure. This pressure is converted into a voltage signal and sent to the Engine Control Module (The computer).

This malfunction is detected when an excessively high or low voltage from the KS is entered to the ECM. Possible causes include...
- the harness or connector (The KS circuit is open or shorted).
- the KS

The KS may be checked with an ohmmeter.

1) Raise the hood. View the engine from the driver's fender. Look into
the deep valley between the cylinder banks and below the intake manifold.
Identify the KS as a black item fastened to the block by a single vertical
bolt. A wire harness wrapped in black leads toward you, out of the valley.
That is the KS sub-harness.

2) Follow the KS sub-harness to it's nearest connector. This is connector F121.
It is located near the upper right-hand corner of the valve cover of the forward cylinder bank, as viewed from the front of the car.

3) Disconnect F121. You have to do a "press the latch and wiggle and
pull" to disconnect it. F121 has only two pins; if you see more than two
pins, you have the wrong connector. Use a digital ohmmeter capable of
measuring more than 10 Megohms. You want to measure the pins of F121, not
the sockets of the matching connector. Measure the resistance between a
good ground (such as the battery negative terminal) and pin #2 of connector
F121. On my car this is the highest of the two pins, the one closest to
the front of the car. The factory spec is 500 - 620 Kohms.

The manual says you have to remove the intake manifold to replace the KS. However, I think that a person with good dexterity and a 10mm ratcheting box wrench could replace the KS without disturbing the manifold.

bill99gxe

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Diagnostic Trouble Code 0307 points to a problem with the Engine Control Module Closed Loop Logic for the Left Bank. The left cylinder bank is also called the front bank. It is cylinders 2,4,6.

DTC 0307 is detected when the closed loop control function for the left bank does not operate even when the vehicle conditions meet the criteria (engine at normal operating temperature, etc.). Possible causes include ...
- Harness or connectors (The sensor circuit is open or shorted.)
- a defective Front Heated Oxygen Sensor sensing element.
- a defective Front Heated Oxygen Sensor heater.

bill99gxe

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Diagnostic Trouble Code 0308 points to a problem with the Engine Control Module Closed Loop Logic for the Right Bank. The right cylinder bank is also called the rear bank. It is cylinders 1,3,5.

DTC 0308 is detected when the closed loop control function for the right bank does not operate even when the vehicle conditions meet the criteria (engine at normal operating temperature, etc.). Possible causes include ...
- Harness or connectors (The sensor circuit is open or shorted.)
- a defective Front Heated Oxygen Sensor sensing element.
- a defective Front Heated Oxygen Sensor heater.

bill99gxe

iTrader: (1)

Diagnostic Trouble Code 0315 points to a problem with the rear oxygen sensor.