Isuzu Rodeo 1999 - DTC 0336 Crankshaft Position Sensor

[IsuRod1999]

Since 4 month the CEL came on from time to time (about one time a week). The only trouble code which is displayed all the times: 0336 - Crankshaft Position Sensor (CKP) Performance. It mostly came on when I start the warm engine again and begin to drive (RPM about 3000), but there is no effect on the performance of the vehicle when the light comes on.

Vehicle:
1999 Isuzu Rodeo
2.2 l, 4 cylinder
manual transmission

I measured already the following voltages on the three wires to the CKP sensor (connenctors unplugged, ignition ON):
Blue wire: 1.36 V DC
Green wire: 1.36 V DC
Black wire: 0 V DC
When the connector is plugged and the enginge is running: I measure almost the same voltages (1.32 V, 1.32 V, 0 V).

I also measured the three wires to determine if there is a short circuit between the wires or a short circuit to ground. But everything seems ok.

Can you tell me whats wrong with my great truck?

Thank you very much for your help.

Robert

[IsuRod1999]

Hello together,

is there anyone with an idea for my problem?

I picked the diagnostic steps out of an Isuzu Repair Manual.
But at the point I am it only told that I have to go to a dealer!

The book said there has to be a supply voltage of about 5 V on the wire to the crankshaft position sensor.
As far as I know the PCM supplies the sensor with the voltage. Is it possible, that my PCM goes wrong??

Or is it more likely a faulty sensor, which has to be cleaned or changed.
Is a defect crankshaft position sensor a common problem with Isuzu Rodeos?

Please be sorry for my bad English, but my first language is German. Would be thankful for any advice.

Robert

[trooperbc]

Originally Posted by IsuRod1999

I measured already the following voltages on the three wires to the CKP sensor (connenctors unplugged, ignition ON):
Blue wire: 1.36 V DC
Green wire: 1.36 V DC
Black wire: 0 V DC
When the connector is plugged and the enginge is running: I measure almost the same voltages (1.32 V, 1.32 V, 0 V).
...Robert

ok, since no one else is charging in here robert. i don't know you're particular engine and haven't specifically tested yet the crankshaft position sensor in my 1992 isuzu troooper 3.2L v6......but....

generally, for many of the isuzu computer components there are three wires.

1. one wire is 5 volts, which is called the reference voltage. it comes from the computer to the sensor
2. the second wire is the responding voltage to the computer, i.e. it's what the computer uses to adjust certain running conditions, e.g. timing, fuel delivery, etc.
3. the third wire is the ground. black is generally the color for ground in the isuzu's, especially for these sensors.

so, you want to put your DigitalVOM ground (black) lead to the black wire; and then you want to put your red lead in turn to each of the other two wires and measure the voltage.
one of those wires will (should) give you the 5 volt reference voltage.
the other of those wires will give various voltages, depending on conditions.
you do these tests with the connector connected to the sensor and the engine running. you can take a reading with the key on, engine off, but it may not give you an accurate value. [[although the 5 volt reference voltage (usually in a range of 4 to 6 volts), should be there with it disconnected, too.]]
the ground wire (black) isn't tested for voltage, of course.

for example, i have recently tested the Manifold Air Temperature (MAT) sensor in my 92 trooper. i backprobed the connector. (***see below)

i tested for the 5 volts. it was there (though the factory manual had the connector Letters reversed, but it didn't matter).
i then tested for the other value, which changes according to the temperature of the air in the manifold at the time. i tested it stone cold and recorded the value. i then tested it several more times as things heated up, both with the engine and the outside air in the sun.
the values for this in the factory manual are not specific (they don't give a set voltage value for a particular temperature). but they should increase or decrease as the temperature changes.

in your case, i have no idea what the value should be. but you do need to test it with the connector connected and with the engine running.

***backprobe if you don't know how to backprobe a connector with the seals in them, as i didn't, check these two threads where i posed the question and got some good responses.

how do you backprobe ?
http://forum.planetisuzoo.com/viewto...980&highlight=

http://www.4x4wire.com/forums/showfl...&Number=927221


i'd like to get a set of those backprobe pins, but i ended up using a paper clip, and in one case a T-shaped pin that is used in sewing to hold fabric in place.


good luck, i hope this is a good start


//bc

[international bus]

Notes Steps 1 - 6
Steps 7 - 9
DTC P0336 Crankshaft Position (CKP) Sensor Circuit Range/Performance


Circuit Description
The 58X reference signal is produced by the crankshaft position (CKP) sensor. During one crankshaft revolution, 58 crankshaft pulses will be produced. The powertrain control module (PCM) uses the 58X reference signal to calculate engine RPM and crankshaft position. The PCM constantly monitors the number of pulses on the 58X reference circuit and compares them to the number of camshaft position (CMP) signal pulses being received. If the PCM receives an incorrect number of pulses on the 58X reference circuit, Diagnostic Trouble Code P0336 will set. Diagnostic Trouble Code P0336 is a type B code.

Conditions for Setting the DTC

• Engine is running.
• Extra or missing pulse is detected between consecutive 58X reference pulses.
• Above condition is detected in 10 of 100 crankshaft rotations.

Action Taken When the DTC Sets

• The PCM will illuminate the malfunction indicator lamp (MIL) after the second consecutive trip in which the fault is detected.
• The PCM will store conditions which were present when the Diagnostic Trouble Code was set as Freeze Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC

• The PCM will turn the MIL OFF on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
• A history Diagnostic Trouble Code P0336 will clear after 40 consecutive warm-up cycles have occurred without a fault.
• Diagnostic Trouble Code P0336 can be cleared by using the Scan Tool's "Clear Info" function.

Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation. Check for:

• Poor connection - Inspect the PCM harness and connectors for improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.
• Damaged harness - Inspect the wiring harness for damage; shorts to ground, shorts to battery positive and open circuits. If the harness appears to be OK, disconnect the PCM, turn the ignition on and observe a voltmeter connected to the 58X reference circuit at the PCM harness connector while moving connectors and wiring harnesses related to the PCM. A change in voltage will indicate the location of the fault.

Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the Diagnostic Trouble Code to be set occurs. This may assist in diagnosing the condition.

[IsuRod1999]

Thanks for the tips. I´ll measure the three wires again next weekend.

Robert

[IsuRod1999]

Finally I found the problem. Perhaps it helps someone else who has the same problem: It was a bad Crankshaft Position Sensor.

In April I had to move back from the US to Germany and I took the good old Rodeo with me. But when the car came out of the container in Germany after 5 weeks of transportion it denied to start. Again there was a P0336 trouble code. The Crankshaft Position Sensor was changed and the car runs perfectly now.

Robert