VTC oil control solinoid valve malfunction

[mr2]

We get the following error message:
Code 56
DTC P0010
Description VTC Oil control Solinoid valve mulfunction

Also further 2 error codes always appear being:
Code 34-2
DTC P0563
Description VBU Voltage high

and

Code 41-1
DTC P1166
Description Heated oxygen sensor sensor1 (primary H02s) heater circuit malfunction

The engine is a standard K24 A2, with TWM ITB and dry sump oil system installed in a Lotus Exige.

As soon as the engine is revved up, the error code shows and the VTC cam angle and Commanded VTC cam angle goes to zero, and the engine cuts out. We checked the wiring which seems fine.

Can you assist to establish what is wrong and what we must do to correct?

The Hondata serial number is 6474 and we use version 1.3.8 software.

[Hondata]

P0563 is because your wiring harness does not correctly wire the main relay so that the ECU gets backup power.

P1166 is from either a bad primary oxygen sensor, or incorrect wiring to the heater / heater relay.

This diagram http://www.hondata.com/images/k20awiring.gif will help you trace those errors.

P0010 indicates that the VTC solenoid is not behaving as expected - the cam position does not match the amount of current the solenoid is using.

You'll need to follow the troubleshooting in the manual, but the first things to check are the VTEC and VTC filter screens for contamination, then the VTC itself for contanimation, then replace the VTC.

[mr2]

Thank you - will check it out

[mr2]

We have now done the following:
- had an expert look at our wiring, and he found no problem. Similarly had AutoECU check our wiring with no problem found.
- Had the ECU bench checked by AutoECU (specialists in ECU repair), and they found no problem. I could not find a car to have the ECU plugged into as we have very few of the relevant K20 engines available in our country.
- We tested the VTC by giving it separate pulse and it does work.
- VTC & Vtec filters are clean

We can still replace the VTC, which is very costly. Do you think the VTC would work but still cause the error message?

The manual is not very helpful in this regard

[Hondata]

The only cause of P0563 is from incorrect wiring or a bad ECU. Try your ECU in a Civic and see if it gets any error codes; if not it is the wiring. Once the first two errors are fixed then look at P0010 in cause it is caused by one of the first two errors.

[mr2]

We fixed both the P0563 & Lambda errors. So they can not cause the P0010 error.

[Hondata]

Good. The next step would be to replace the VTC solenoid.

[mr2]

We tried my ECU on another car, and it worked fine. We also installed my VTC solinoid on the other car, and got no error messages. The cam controller and cam angles operate as it should etc. That indicated that the ECU and VTC solinoid is ok, and that the problem should be wiring.

We followed the DTC troubleshooting guide, and found the following:
Step 5 - found appropriate measurements
Jumped to step 10 - There is no continuity, which indicates a problem with the ECU.

But we checked the ECU with another car and it was fine, so we are now really stumped!

Is there something else we can try?

[Hondata]

What ECU are you using, and how is the VTC wired? In the US the wiring is different for the VTC between 02-04 and 05-06 vehicles; in the UK it should be the same for all models, but it is worth checking.

[mr2]

We are using the Kpro ECU with Hondata serial number 6474. Wiring of the VTC solinoid is onto pin 1 & 23. The engine is a K24 A2. The engine is a Japanese import model (not sure what year model)

[mr2]

Are we using the correct pins (1 & 23 on connector B)?

Can there be something else we can test which could cause this error?

We are now certain that:
- The VTC is fine (tried it on another car)
- The ECU appears to be good (loaded it on another car)
- We have the VTC connected to pins B1 & B23 on the ECU.
- The resistance reads between 7 & 10.2 ohms between terminal B1 & B23
- There is no continuity between connector terminals B1 & B23 and body ground individually.
- We are using V 1.3.8 software
- We still get the DTC P0010 error message.
- No other error codes appear

We are now at the point where we need to decide, and may throw out Hondata as we are about to give up with it.

Come on guys, please get us out of this mess!

[Hondata]

The B connector wiring should be part of the factory harness.

Go back to my first post - P0010 means that the VTC current does not match the cam position. It still could be a number of meachanical issues with the engine - the intake cam sprocket itself, oil pressure at the VTC solenoid, oil passages to the intake sprocket, freedom of cam rotation, cam timing etc. Also consider than testing wire continunity does not verify the current flow under load. Eventually one side of the VTC gets grounded, so also check the master ground (intake manifold / valve cover) and the paths from that ground to the chassis. There should be three grounds from the engine - engine mount, transmission and valve cover. Being a Lotus, you'd also want to clean up around the main ground stud in the engine bay, as I had to remove the anodizing around mine for a good connection.

[mr2]

We opened the ECU and started the engine (revving it up and down). There is no signal from the VTC pins going out of the ECU box (pins 1 & 23).

At the same time we know that the ECU is working in another car.

Earth was checked and we added additional earth wires to make sure.

That indicates a wiring problem elsewhere and the ECU is probably not getting a signal to cause the VTC to operate.

We also reckon it indicates that the problem is not VTC, VTC wiring, cam pulleys, oil pressure, mechanical issues, etc.

We have no other error codes (other than P0010). Note that the P0010 error comes up even when the engine is not running.

Are you able to guide me to which other wiring it could be (to date we concentrated on the VTC wiring only)?

[Hondata]

What wiring harness was used? Is it the same as an 02-04 RSX engine harness?

[mr2]

We used K24 harness plugs and wired the rest. I have a K20 (2002 to 2004) harness arriving tommorrow which we will then use.