DIY PGMFI Diagnostics - Code 9 CYP

[ECU-MAN]

Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!


No part of this DIY is to be reproduced with out acknowledgment of the site and author it came from, ie me and ozhonda.com. Do not rip parts off and claim them as your own.




CYP Sensor "Cylinder Position". Also known as CMP. The CYP sensor is commonly located on the side of the head, inside the Distributor. Not to be confused with the CKP or TDC sensor that is also located in the distributor, or in its own housing driven by the exhaust camshaft. The CYP is a magnetic pulse generator type of sensor. The ECU monitors the CYP to determine the cylinder position of #1 cylinder for injector duty and ignition timing trim.
Bellow is a picture of an CKP CYP TDC sensor in a B16A2 Distributor. The yellow arrow is pointing to the CYP magnetic pickup and the pulsar.






Aim:

Diagnose code 9.





Required:


Basic Testing

- Digital Multi Meter
- Tachometer ( vehicle tacho can be used )
- paper clip


Advanced Testing

- all the above
- oscilloscope or wave form viewer


Symptoms

For a faulty CYP sensor to trigger code 9, you will more than likely get the engine light come on and the car will go into limp mode, Limp mode is a preset fuel and ignition map running on a backup processor in the ECU. Limited to about 3500rpm and a rich mixture to protect the engine the engine will run, but not the best. Common cause for code 9 is a damaged CYP from distributor bearing failure or open circuit in the sensor or wiring back to the ECU.



Basic Test


- Perform a Visual inspection and make sure the CYP sensor is Connected, listed for metallic sounds from the distributor. Save yourself allot of time, If you have a very noisy distributor with lots of grinding metallic sounds, replace your distributor.


CYP Sensor Pin out Picture

OBDO




OBDI





wire side of connector


( note, unfortunately TDC sensors come in a variety of different connectors for different types for Honda's. In this DIY, I have just covered the basic all in one distributor. If you have a 4 wire distributor, Legend ect, reply to this thread and I’m sure some one will be able to help. )



**** Resistance Test **** Set the multi meter to ohms ( 2k scale )


Unplug the CYP sensor, connect your Red multi meter lead to the CYPP. Connect your Black multi meter lead to the CYPG.


CYPP

OBDO = Pin 4
OBDI = Pin 1
OBDII = Pin 1


CYPG

OBDO = Pin 3
OBDI = Pin 2
OBDII = Pin 2

their are two types of sensors.

350ohm to 750ohm ( most Honda's are 350ohm to 750ohm)

or

700ohm to 1300 ohm


If your TDC is not with in spec replace it ( or the distributor ). To be safe, consult the workshop manual for the actual specs for you CYP.



**** Voltage Test ****


Set your multi meter to AC Volts ( 20v scale )

Step 1


Check the CYP sensor for its output Voltage to the ECU, Connect the Black Lead from your multi meter to the chassis for a good ground. Back probe* the CYPP ( Cylinder Position Power) with the Red lead while the sensor is connected.



OBDO = Pin 4
OBDI = Pin 1
OBDII = Pin 1


KOER* at idle ( 800RPM ) you should get about 0.7vac
KOER* at 2500RPM you should get about 2vac



You can also test the CYP signal at the ECU connectors


OBDO = A10
OBDI = B11
OBDIIa = C4
OBDIIb = C29


If you do not get a signal, replace the CYP ( distributor )


**** Frequency Test ****


Set your multi meter to Hz scale


Step 1


Check the CYP sensor for its output frequency to the ECU, Connect the Black Lead from your multi meter to the chassis for a good ground. Back probe* the CYPP ( Cylinder Position Power ) with the Red lead while the sensor is connected.


OBDO = Pin 4
OBDI = Pin 1
OBDII = Pin 1


KOER* at idle ( 800RPM ) you should get about .015khz
KOER* at 2500RPM you should get about .021khz


You can also test the CYP signal at the ECU connectors



OBDO = A10
OBDI = B11
OBDIIa = C4
OBDIIb = C29



If you do not get a signal, replace the CYP ( distributor )


**** Continuity Test ****




Set your multi meter to continuity. This setting is mostly a picture if a sound .))) when you touch the Red and Black leads together on your meter it should beep.


STEP 1

make sure the Ignition is off and unplug the CYP Connector and the ECU Connectors for this test

Continuity test between CYPP and ECU, Connect your Red multi meter lead on the CYPP, Back probe* the Black multi meter lead on the ECU Pin bellow that suits your car.





OBDO = A10
OBDI = B11
OBDIIa = C4
OBDIIb = C29




your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.



STEP 2

make sure the Ignition is off and unplug the CYP Connector and the ECU Connectors for this test


Continuity test between CYPG and ECU, Connect your Red multi meter lead on the CYPG, Back probe* the Black multi meter lead on the ECU Pin bellow that suits your car.




OBDO = B12
OBDI = B12
OBDIIa = C14
OBDIIb = C30




your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.




Advanced Test






You may pass all the above test with no problems at all. Unfortunately this does not mean all is well. You can have a sub code to the code.

example code 9 -1

code 9 is TDC

sub code 1 ( for example, ) is noisy CYP


You will not get sub codes from the SCS and MIL, you need the HDM or PGMFI Tester from the DLC port.

So in this advanced test, we are going to test the CYP with an Oscilloscope or Waveform Viewer to look at the signal generated from the CYP close up. The aim is to get a nice clean sine wave with out any glitches or drop outs.

Common causes of noisy sensors are rebuilt distributors. Once the bearing has failed and the pulsar has gone to town on the magnetic pickup and has damaged the pulsar and pickup assembly. Just changing the bearing in a dizzy rebuild sometimes doesn’t cut it. Also cracks in the sensor housing is a bad thing.

Test Time

Connect the Black Lead from your waveform viewer to the chassis for a good ground. Back probe* the CYPP ( Top Dead Centre Power) with the Red lead while the sensor is connected.



OBDO = Pin 4
OBDI = Pin 1
OBDII = Pin 1


KOER, you should get a pattern that looks abit like the pattern in the pic bellow.






you should not get a pattern with glitches or fuzz in the sine wave like in the pic bellow. if you do replace the sensor/distributor







* Notes

KOEO = Key On Engine Off

KOER = Key On Engine Running

Back probe the sensor, use a paperclip and push it into the connector then touch/clip your multi meter lead to the paper clip


Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!