UK 99 C5 Manual resto project

[teamzr1]

I'd like to buy a PCM flashing tool and have access to this software - Where can I get it from?

If you're serious in doing more with the electronics in vehicles of the last 30 years, you need at least 2 tools

1. OBD-II full scanner and recorder
Works best with a laptop that has MS Windows but also has an APP to work on a cellphone

This scanner uses Bluetooth, so laptop and cellphone have to have BT

OBDLINK MX+ is the scanner, about $140 US

https://www.amazon.com/OBDLink-Bluetooth-Professional-Grade-Diagnostic-Performance/dp/B07JFRFJG6/ref=sr_1_2?crid=3SM7FEF21L9S1&keywords=obdlink+mx&qid=1675185555&sprefix=obd%2Caps%2C117&sr=8-2

Tools to make changes to GM calibrations for PCM and TCM are not cheap, not many vendors make and sell them as fricking governments hate people doing changes that affect smog laws

I have been doing custom tuning since 1995, you cannot go to any school and learn how to do this and this means you cannot buy a tuning tool and become a pro in doing so and many times people screw their vehicles up using the vehicle as a learning process

IF your interest is having a tool that does not allow you doing the tuning but have someone like me do the custom tunes, and you use a tuning flash only tool, than here is the tool you want
This would allow for you or anyone who comes to you with a GM gas based engine from like 1996 to abut present

Simply you would use the scanner, in record mode and drive the vehicle and scanner collect engine and tranny data,
that become a recording file, can be played back later or emailed to like me to analyze and know that exactly what changes to make in the tune

You then need this tool

TunerCat

On the left, select the "OBDII Dealer Kit"
You're buying this from that vendor, not me
It is not cheap, they do ship to the UK

This comes with cables, hardware interface (plugs into the DLC under the dash) and software

With this tool and your laptop, it allows you to read the PCM or TCM, it becomes a file that you email to me
I then do all the tuning, email the new tune, and you use that tool to program that into the controllers and you're done
Most case if totally stock vehicle a custom tune will increase flywheel HP by 30 and higher torque from low to upper RPMs and gain fuel mileage

 

[teamzr1]

Can I just say THANK YOU for all your efforts in hekping me here, it is much appreciated!! Great to have a knowledgeable guy on hand who is willing to help

I do have a buddy with me who helps with the testing so I ask him to turn the key on/off etc when checking voltages. I never get any voltage to the relay coil, not for priming or running. Literally no 12v ever appears at that terminal

Agreed

I haven't checked the clutch switch but it seems to operate okay by preventing cranking without the clutch depressed, I can bridge it out and try anyway though I guess, just to eliminate it as an issue!

Excellent idea - I will do this when I am next with the car (most likely weekend)

I will double check but every fuse in both fuse panels inc. the maxifuses have all been continuity checked and seem to be ok

All pins are clean and correctly seated, I didn't really show on camera but I spent a lot of time cleaning up those harness plugs and they are really in excellend order now given how bad they were. Pins PCM side are all looking straight and correct as well


I think this is a great idea actually, I will try and do this now the PCM is fuly dried out. I can see a blown resistor on it but I reckon it's still worth a go for sure. I will do this and report back. I will also run a DIC code check as well and make a note of them...

So you have one issue known to be fixed, but you could move on to make sure there is no other problems

Would be a lot easier if having that OBD-II scanner to trap all this data

Jumper and start engine, it will be in "open Loop" the PCM ignores all the feedback sensors like MAP, MAF, O2 sensors, IAT, etc
Wait until coolant temp gauge shows at least 160 F deg, at that time PCM goes into "Closed Loop" and begins to use feed back sensors which means in your case the PCM has to start learning and adjusting to what the sensors report to PCM
Normally take PCM good 5 plus minutes to start adjust fuel and idle RPMs.

Turn A/C on to full blast, even in cold weather the drag of A/C compressor will cause MAP changes and cause different fueling and RPMs for them
and see if the HVAC doors change as you go through A/C, Heat and Defrost

If doors are not redirecting, then the vacuum hose which is the wire loom by PCM may have been melted by acid (common to happen) and also affect how the engine runs.

How old is the gas, if has Ethanol, that crap grows in the fuel system, I notice in your video new parts in hatch, one is the fuel regulator/filter
you may have to change it, mounts on rear left side of frame, need a tool to release fuel lines from both sides.
If gas is too old, you might have to drain and put in gas in

If after idle relearn, maybe drive it and see how everything is functioning
Look to see if all gauges on dash report correctly, also via the DIC buttons look to see if all functions look OK

Before tuning engine off, check and write down all DTCs for all controllers
Do not disconnect battery, as PCM then loses all it relearned and forces all on-board smog tests to start also relearning

 

[Llewelyn]

So you have one issue known to be fixed, but you could move on to make sure there is no other problems

Would be a lot easier if having that OBD-II scanner to trap all this data

Jumper and start engine, it will be in "open Loop" the PCM ignores all the feedback sensors like MAP, MAF, O2 sensors, IAT, etc
Wait until coolant temp gauge shows at least 160 F deg, at that time PCM goes into "Closed Loop" and begins to use feed back sensors which means in your case the PCM has to start learning and adjusting to what the sensors report to PCM
Normally take PCM good 5 plus minutes to start adjust fuel and idle RPMs.

Turn A/C on to full blast, even in cold weather the drag of A/C compressor will cause MAP changes and cause different fueling and RPMs for them
and see if the HVAC doors change as you go through A/C, Heat and Defrost

If doors are not redirecting, then the vacuum hose which is the wire loom by PCM may have been melted by acid (common to happen) and also affect how the engine runs.

How old is the gas, if has Ethanol, that crap grows in the fuel system, I notice in your video new parts in hatch, one is the fuel regulator/filter
you may have to change it, mounts on rear left side of frame, need a tool to release fuel lines from both sides.
If gas is too old, you might have to drain and put in gas in

If after idle relearn, maybe drive it and see how everything is functioning
Look to see if all gauges on dash report correctly, also via the DIC buttons look to see if all functions look OK

Before tuning engine off, check and write down all DTCs for all controllers
Do not disconnect battery, as PCM then loses all it relearned and forces all on-board smog tests to start also relearning

Thanks for the info - I'll give all this a go. Makes sense to let the car run up to temp. I don't think the gas is that old but could be 6 months old which if it is E10 isn't great!

Re the scanners I have an OBD CX but I'm not sure if it's compatible with TunerCat... I'll have a look. I don't mind investing a few hundred ££ into scanning software etc, I'd rather do that and learn (I don't want to tune or customise, I just want to be able to fault find really). I've also got an Autel Maxlink but it's quite a basic model. I bet it will still read all the DIC codes though. It does have live data but what you can see tends to be quite limited in my experience.

 

[teamzr1]

The OBDLINK CX version is designed to be used with BMW and some other non-American vehicles, from 2008 and newer as to sellers information

The OBDLINK MX+ is slanted for American models

 

[Llewelyn]

The OBDLINK CX version is designed to be used with BMW and some other non-American vehicles, from 2008 and newer as to sellers information

The OBDLINK MX+ is slanted for American models

Aha! Makes perfect sense I will buy an mx+ then... The CX works very well, they seem like excellent products

 

[Llewelyn]

A very protracted update - But... it RUNS! Normally, with no faults

I've spent basically no time on the car since my last post/video due to life getting in the way and me being just too busy to even get to the car (it was stored at my other half's parents) however there has been a flurry of activity over the last week and here is a recap:

After the last video (part 3) where I still couldn't get the fuel pump to energise I decided to take BOTH PCM's to an ecu specialist and have the program from the broken PCM flashed onto the new one. What this did for whatever reason was completely brick the new Flashmasters PCM and when installing it I could not clear a P0606 H C error this could either be an error the ECU tecchie made or some sort of corrupt file. Anyway it was screwed.

I then purchased a Tech2 with TIS2000 thinking I could reflash the new PCM using TIS2000. It took me a while to get all the software configured, I had to use virtualbox on an old laptop with an RS-232 port and run Windows XP inside Windows 10. I installed TIS2000 into XP which was a right pain, especially getting the license key to work. I then had to figure out how to get the serial comms working in the virtual OS which again was a major headache and I solved it with a serial to USB dongle which worked a treat and was very stable (some people have had mixed results with this).

Attempted reflash and the PCM just would not take the upload and it would crash halfway though so I think the PCM is toast.

Bit the bullet and purchased another PCM from Flashmasters!!!

I had a separate issue with the passenger door not working and I used the Tech2 to try and see what was going on with it. It turns out there was no communication at all to the RDCM door module so I started digging around and found a dodgy connector in the door loom accordion so I cleaned it up and reset the pins and the door came back to life.

Back to the new PCM - All happened VERY quickly... I plugged it in, carried out the theft deterrent relearn and away she went!! Amazing result!!

Now, whether the door module was causing serial data confusion originally and that was why the first replacement PCM wouldn't work, I've no idea. But at this point the car runs and drives really well and I don't care!

IF ANYONE NEEDS TECH2 DIAGS IN THE MIDLANDS DROP ME A PM, HAPPY TO MEET UP AND I WON'T CHARGE YOU

For those interested here is my part 4 video!

 

[C5Steve]

Great to hear it's back up and running and you didn't give up! Looking forward to watching the video later.

 

[teamzr1]

When the flash from the original PCM was read and then flashed to the first one you bought, caused the P0606 DTC
a scanner should have been used and the freeze-frame that would have triggered and analyzed what it reported
Also IF voltage to PCM was low and flashing is done will cause data movement to corrupt data bits

GM over life of a model does software updates (TSBs)
The PCM like a PC has an operating system, and then 7 other software code segments
When updates are done, it could be only the main OS getting updated or maybe one of the other segments

This now means that PCM has different versions of the above and the new one could have different updates
so it now is not apples to apples from the 2 PCMs
If the proper flashing was not done than the new controller getting flashed is like for example a file from MS Windows 7
being copied over to MS Windows 10 would then screw up Ver 10 OS as now a mismatch

What should have been done is being you have a TECH-II is flashed the first new PCM with a GM supplied calibration
that would have the correct version of the OS and all updates to any of the 7 code segments.

I would do ( can be done as Off-Board ) (PCM not in the car) is now, use the tech-II and do as above so that you now have a
functional spare PCM

It is common for water to get inside the doors and corrode wiring pins
I would have suggested that after cleaning up the connectors is wrap them in plastic to reduce any water getting into them in the future

In the end, glad you have your C5 functional
What is needed now is assuring the calibration now used is allowing the engine to correctly, so need to use a OBD-II scanner
and make sure looking at the fuel trims that the engine is not running too lean or rich, having misfires or engine knocks or timing is off

Also with tech-II and if you paid GM for a per vehicle use service access is use it to have the tool look at the PCM OS and code segments version and have it then flash in all updates/ TSBs so the PCM is up-to-date.

IF the engine does not function best for performance than it comes down to I mention is the calibration being custom tuned (Keith of Eurovettes has tuning tools) and I can tune than via emails

 

[Llewelyn]

When the flash from the original PCM was read and then flashed to the first one you bought, caused the P0606 DTC
a scanner should have been used and the freeze-frame that would have triggered and analyzed what it reported
Also IF voltage to PCM was low and flashing is done will cause data movement to corrupt data bits

GM over life of a model does software updates (TSBs)
The PCM like a PC has an operating system, and then 7 other software code segments
When updates are done, it could be only the main OS getting updated or maybe one of the other segments

This now means that PCM has different versions of the above and the new one could have different updates
so it now is not apples to apples from the 2 PCMs
If the proper flashing was not done than the new controller getting flashed is like for example a file from MS Windows 7
being copied over to MS Windows 10 would then screw up Ver 10 OS as now a mismatch

What should have been done is being you have a TECH-II is flashed the first new PCM with a GM supplied calibration
that would have the correct version of the OS and all updates to any of the 7 code segments.

I would do ( can be done as Off-Board ) (PCM not in the car) is now, use the tech-II and do as above so that you now have a
functional spare PCM

It is common for water to get inside the doors and corrode wiring pins
I would have suggested that after cleaning up the connectors is wrap them in plastic to reduce any water getting into them in the future

In the end, glad you have your C5 functional
What is needed now is assuring the calibration now used is allowing the engine to correctly, so need to use a OBD-II scanner
and make sure looking at the fuel trims that the engine is not running too lean or rich, having misfires or engine knocks or timing is off

Also with tech-II and if you paid GM for a per vehicle use service access is use it to have the tool look at the PCM OS and code segments version and have it then flash in all updates/ TSBs so the PCM is up-to-date.

IF the engine does not function best for performance than it comes down to I mention is the calibration being custom tuned (Keith of Eurovettes has tuning tools) and I can tune than via emails

Thanks for the info - That makes perfect sense. I am glad to hear you haven't completely lost faith in the "new" PCM.

Early days yet but all seems to be okay, it isn't down on power and there is no typical symptoms of ill engine health... I think what I need to do now is properly soak test it and use the car regularly to give it a shakedown.

Re the door I do need to go back in there to sort the speakers out and check the window alignment etc so I might see if I can pot those connectors somehow - You can clearly see the moisture damage on them!

 

[teamzr1]

You have spent a lot of time and money and also got the diag tools

You really cannot tell how well the engine really is functioning long term, and before you forget how to work on this
be best to get a scanner in record mode, do a testrun, including WOT and tell how the fuel trims, etc are

People buy a Corvette to use that V-8, not just what engine can do cruising around, so include some WOT pulls
in scanner recording will tell what is needed which could find out fuel injectors are clogging up at higher RPMs to
inducing more knock and/or misfires

 

[Llewelyn]

You have spent a lot of time and money and also got the diag tools

You really cannot tell how well the engine really is functioning long term, and before you forget how to work on this
be best to get a scanner in record mode, do a testrun, including WOT and tell how the fuel trims, etc are

People buy a Corvette to use that V-8, not just what engine can do cruising around, so include some WOT pulls
in scanner recording will tell what is needed which could find out fuel injectors are clogging up at higher RPMs to
inducing more knock and/or misfires

Thanks - I will check everything in due course. I'm not an LS1 expert, this is my 2nd manual C5, and still learning how the diags work etc.

The car pulls clean and hard up to the redline without any issues so it at least appears to be in rude health.

 

[Llewelyn]

Part 5 now online if anyone is following…!

 

[Yellowshark]

Hi Llewelyn, nice job but I am wondering why you did not fit the seats the other way around so that the "new" looking seat is the driver seat? Or are the wiring connectors under the seats not the same. ? It is something I have been meaning to do on my C5 for years and your video has inspired me

 

[teamzr1]

Have to consider the controls / switches on the lower outer side of seats would be on the wrong side of seats if swapping positions
That would mean the right seat controls mounted on the left side would be hidden by the center console, same for other seat

Also have to see if the YAW sensor mounted under right seat could be moved to the left seat now going to right side

 

[Yellowshark]

Thanks teamzr1. Typical all best laid plans written in sand. So maybe one could go to an upholstery shop and have them just swap the leather over plus the pad pouches that give you the adjustments; does that sound doable? Or are the cuts in the leather for the exterior controls different between sides, I suspect. Maybe the easiest thing is just to buy a new drivers seat, which sounds rather expensive. My passenger seat is as it left the factory

 

[teamzr1]

Controls for the seats are on the outer side, part of the seat frame and not sure if there are any holes in the leather for the control wiring or not
So swapping seats left/right would not work

My 1999 Drivers seat

 

[Llewelyn]

Hi Llewelyn, nice job but I am wondering why you did not fit the seats the other way around so that the "new" looking seat is the driver seat? Or are the wiring connectors under the seats not the same. ? It is something I have been meaning to do on my C5 for years and your video has inspired me

Thanks for watching - Glad I've inspired you to sort your seats out! Wiring connectors are different which is probably sortable but there is also the telescopic memory on the drivers seats which is a second connector not featured on the passenger side More importantly the electric seat switches are on the wrong side so some trimming would be needed to sort that out...

My old set are for sale but they will need new foams and a set of covers. I'm after £100 if anyone is interested