Morning all.

 

I've already posted this elsewhere and had a couple of answers, but thought I'd pick your brains as well (I'm not great with electronics!)

 

So since putting my Z in for its MOT its developed the usual heavy steering at low speed/intermittent speedo drop out fault. My first thought was speed sensor as it's a fault I've had on my previous Z.

 

I decided to investigate further by hooking up to ConZult (cheers BigH) and conduct a HICAS diagnostic (can't do an Engine diagnostic via Conzult as I'm on a Haltech). This is a shot of what it was displaying. Diagnostics was done with the vehicle stationary and idling with the front wheels pointing straight ahead. Car is fitted with a HKB steering boss and after market wheel (has been fitted for 5 years with no previous issues)

 

 

A couple of things are apparent that I'm looking to figure out why I'm getting such readings.

 

1) vehicle speed showing as 11mph whilst vehicle is stationary

2) engine rpm shows as greater than 1500rpm whist car is idling at 750rpm

3) steering angle showing as 7323 degrees to the right, yet it's detecting the steering angle sensor is in the neutral dead ahead position

4) if I accelerate, the speedo responds as expected and is bang on when compared to GPS, yet Conzult detects no change in speed, nor does it detect any movement if I turn the wheel left to right

 

FunkySi has already suggested that I look for dry solders on the speedo, which I will investigate/resolve.

 

However, the other issues currently have me baffled.

 

Any ideas?

What type of clocks do you have ?

 

Is it a UK or Japspec ?

 

If its Japspec do you have a speedo convertor in place to convert from Kph to Mph ?

 

If not I would check the clocks and make sure everything is screwed down or connected tight and also look for damaged tracks or bad soldering.

What type of clocks do you have ?

 

Is it a UK or Japspec ?

 

If its Japspec do you have a speedo convertor in place to convert from Kph to Mph ?

 

If not I would check the clocks and make sure everything is screwed down or connected tight and also look for damaged tracks or bad soldering.

 

 

95 series 4 JDM buddy.

 

Yeah I'm going to check the PCB on the clocks for dry solders etc. I forgot to take a pic of the converter that's been used, but it didn't look like a cheap nasty one, all properly wired in and shrink wrapped etc..... but it's certainly a possibility.

 

It's the steering side of things that has me confuddled. I'm assuming the steering angle sensor goes straight to the Hicas computer?

FunkySi has already suggested that I look for dry solders on the speedo, which I will investigate/resolve.

 

 

This might help you. I am not too sure whether the PCBs are identical. Groover would know.

 

https://www.300zx.co.uk/forums/showthread.php?157208-clocks-doesn-t-work-(&p=1747265&viewfull=1#post1747265

I've had similar issues with a speedo convertor that previously worked.

 

Just to check ensure the speedo convertor is powered from the 2 of the 4 cluster bolts rather than the two at the bottom of the cluster.

 

The two at the bottom are for the backlights and are variable voltage so they wont power the unit properly.

 

I discovered this after six months when someone dimmed down my cluster using the buttons on the right pod and my speedo went wonky.

 

Soon as I put the cluster to full again using the controls it started working again.

 

 

 

95 series 4 JDM buddy.

 

Yeah I'm going to check the PCB on the clocks for dry solders etc. I forgot to take a pic of the converter that's been used, but it didn't look like a cheap nasty one, all properly wired in and shrink wrapped etc..... but it's certainly a possibility.

 

It's the steering side of things that has me confuddled. I'm assuming the steering angle sensor goes straight to the Hicas computer?

Well I removed the speedo this arvo. This is the converter I have fitted

 

 

I also left the battery unhooked over night with the wheels left straight (apparently it can confuse the hicas ecu of where the steering angle sensor is pointed if you disconnect with wheels pointed off centre), but to no avail.

 

Looks like I'll have to go through the whole WSM trouble shooting and check every system. I hate electrics

To clarify, I haven't fitted that converter, I mean that's the one that was fitted to the car when it was imported

Ok, well this is interesting.

 

So it appears that with speedo converters, while they correct the speed signal going to the actual dial, they don't correct the signal going to the HICAS ecu.

 

 

Where's Groover when you need him!

not sure what that steering angle is about...I have never seen it that high.

Almost looks like the angle sensor has failed or something..or maybe a faulty HICAS ECU (because of the vhcl speed issue)

Does the value change when you turn the wheel ? ...or maybe try a different HICAS ECU

 

Also the HICAS ecu expects a rpm signal from the (original) engine ECU, but as you have a haltech that is not going to work anymore, unless it has programmable output that can be used to generate a similar RPM signal for the HICAS to recognize and use.

 

(PS: There's a slight change the missing RPM signal is the cause of all these faulty readings.)

not sure what that steering angle is about...I have never seen it that high.

Almost looks like the angle sensor has failed or something..or maybe a faulty HICAS ECU (because of the vhcl speed issue)

Does the value change when you turn the wheel ? ...or maybe try a different HICAS ECU

 

Also the HICAS ecu expects a rpm signal from the (original) engine ECU, but as you have a haltech that is not going to work anymore, unless it has programmable output that can be used to generate a similar RPM signal for the HICAS to recognize and use.

 

(PS: There's a slight change the missing RPM signal is the cause of all these faulty readings.)

 

No, the value doesn't change at all. I am wondering if the Haltech is causing an issue with the readings the Conzult is producing. I would have expected that with them being so far out it would have triggered "fail safe" mode and thrown up the HICAS light, which it has never done. It's things likely saying the parking brake was engaged when it wasn't, nor any change when I engage/disengage the clutch or brake pedal.

 

I'm going to send Haltech an email asking if the Platinum plug in ecu properly "speaks" to the hicas ecu.

 

Do you happen to know if I need the engine running to engage the diagnostics mode with Conzult, or does could I just do it with the ignition on (so I could plug in my original ECU and see if I get any different readings)

 

For the mean time, I'm going to look at doing the same "permanent" modification the Skyline boys do and remove the J4 resistor from the circuit board and bridge some of the other connections to recalibrate the speedo, therefore ensuring an unaltered signal to the ecu

 

- - - Updated - - -

 

From there, I'll just look at working through the troubleshooting pages in the WSM and make sure everything is sending the signals to where it's meant to etc and go from there

Do you happen to know if I need the engine running to engage the diagnostics mode with Conzult, or does could I just do it with the ignition on

 

monitoring sensor values and reading errorcodes work with just the ignition on.

For actual diagnostics, it is preferred to have the engine running.

Well the official word from Haltech is that their ecu should have zero influence on the rest of the Conzult systems diagnostic capability and the Platinum Pro plug in is calibrated to read the vehicle speed sender via one of the options within the ecu manager.

 

I think I'll try and plug my original ecu back in and see if it makes any difference to the Conzult and the diagnostic results, otherwise I'm going to have to do as I mentioned above and manually check each component with a multi meter and cross reference with the WSM

 

OH THE JOYS

Little update

 

I have put and new speedo converter in. This one corrects the speedo but sends and uncorrected speed signal to the ECU.

 

However, whilst I no longer have any speedo drop out, I still have heavy steering.

 

Conzult still shows the same readings as per the first post.

 

Looks like I'll be going through the car with a multi meter.

 

I'd usually consider trying another HICAS ECU, however, being a s4 car with electronic Super HICAS, the ECU is completely different to hydraulic hicas ECU

 

I've tried taking the HICAS fuse out to "deactivate" the hicas, but symptoms remain the same..

 

Anyone else got any bright ideas?

How heavy is 'heavy'? My HICAS is currently unplugged, however mine is S1, so a different system.

 

I can't recall, but isn't there a valve that regulates sensitivity on the rack? PAS solenoid? Could that be faulty?

Only skipped through this thread quickly but what sticks out is there is a general confusion about the hicas and the heavy steering, so starting with the steering angle reading, the hicas cannot work with that reference signal end of. It is basically telling the hicas that the steering is constantly on a heavy right hand angle that is not achievable known as an implausible signal so the hicas will see this as a fault and switch off.

 

This is not anything to do with the main steering been heavy, this is the hicas only and is dealt with by a different part of the hicas / steering ecu.

 

The main steering reduced assistance can activate if a loss of speed signal occurs of course and considering the car set up this should be tested at the steering ecu, look for a 1 to 5 volt AC signal on the correct cable, if there is a problem with the speed signal the steering will feel ok until the car builds up some speed and then it will fault and go hard.

 

The steering solenoid is responsible for the change over of assistance and this should be checked, it operates at around 5 volts, and is fitted to the end of the steering rack on the drivers side, could be simply a failed solenoid or cable fault, or even unplugged??

 

When fault finding it is so easy to end up going way off track, go to the source of the issue ( steering rack solenoid ) and work back from there...

 

 

Jeff

Edited September 1, 20178 yr by JeffTT

Only skipped through this thread quickly but what sticks out is there is a general confusion about the hicas and the heavy steering, so starting with the steering angle reading, the hicas cannot work with that reference signal end of. It is basically telling the hicas that the steering is constantly on a heavy right hand angle that is not achievable known as an implausible signal so the hicas will see this as a fault and switch off.

 

This is not anything to do with the main steering been heavy, this is the hicas only and is dealt with by a different part of the hicas / steering ecu.

 

The main steering reduced assistance can activate if a loss of speed signal occurs of course and considering the car set up this should be tested at the steering ecu, look for a 1 to 5 volt AC signal on the correct cable, if there is a problem with the speed signal the steering will feel ok until the car builds up some speed and then it will fault and go hard.

 

The steering solenoid is responsible for the change over of assistance and this should be checked, it operates at around 5 volts, and is fitted to the end of the steering rack on the drivers side, could be simply a failed solenoid or cable fault, or even unplugged??

 

When fault finding it is so easy to end up going way off track, go to the source of the issue ( steering rack solenoid ) and work back from there...

 

 

Jeff

 

Cheers Jeff

 

With regard to the clearly pish steering angle potentially triggering the failsafe on the HICAS system, would this not trigger the HICAS dash light?

There is definitely SOME pas assistance, it's not completely dead. I can feel a change in resistance in the steering wheel when starting the engine, just feels like it's on absolute minimum assistance

There is definitely SOME pas assistance, it's not completely dead. I can feel a change in resistance in the steering wheel when starting the engine, just feels like it's on absolute minimum assistance

 

Ok, just to clarify the power steering has two assistance levels they we need to deal with, low and high speed, low been easier of course, however if there is any doubt in the systems ability it will default to the lower setting, this is to prevent it not reducing assistance at high speed which would be lethal on the motorway.

 

So if your in the lower assistance from the off it has nothing to do with speed signals, change of wheel, or ecu fitted, get a meter across the solenoid and see if it has a base 5 volts, if not that is why there is little assistance the cause needs investigating as mentioned before, if there is a 5 volt signal and the fault is there the solenoid has likely failed, this can be confirmed by unplugging and doing a resistance check on the solenoid windings, good news if the solenoid is faulty its easy to change.

 

 

These kind of faults often become a big deal as small amounts of internet knowledge can be a bad thing, used to have many owners in the workshop in the day pulling their hair out at a fault that we would trace within a few minutes, when explained in depth what was going on the penny would drop how they had been way off course, ConZult is a great tool, but most people do not how to use it fully ir even understand it, the obvious faults or "wrong" readings are just indicators and not answers, after years of using the system every single day you tend to interpret it in a very different way to most DIY

owners.

 

 

Jeff

Edited September 1, 20178 yr by JeffTT