erratic +5v Link Storm Black

[Tom H]

Hi, 

I have a link Storm ECU and its been in the car for around 4 years, purchased 5 years ago. The configuration hasn't changed until an E throttle was added about 2 months ago. After the conversion the car still ran fine until now. 

The car started faulting error 74 which initially could be reset from the ECU. its now solid and cant be removed. 

I have unplugged every sensor off the engine and the fault remains, along with the other AN faults since sensors are open (disconnected). with all sensors plugged in and/or unplugged the +5v from the ecu reads about 1.4-2.5V on a multimeter and the runtime screen on the PC link software shows a fluctuation between 0-5v about every second. 

My next step is to remove the ECU from the car and bench test, just to rule out external wiring concerns. I will try do this in the next 24 hours. On the assumption that the fault (5v swing)will remain what are my next options? return ECU for Link gurus to fault find? 

From the above, what is the maximum load the +5v and sensor ground can take? There are 2x +5 and 2x sensor grounds from memory on the Storm but I cant remember how the devices connected to them were shared in my build. ie, no idea on loading or if sharing the loading is a concern, assuming they are common within the ecu. If excessive load was an issue would the ECU do what I am seeing or would it just fault and shut down or could the +5v Tracks, or the sensor GND tracks or components fail. 

on the circuit is 

• TPS x 2
• APS x 2
• Oil and Fuel pressure 
• Innovate AFR 

Any help appreciated.. 

201212 fault evo x Evo tune E Throttle.pclr

[Adamw]

Yes, if the 5V output is overloaded it will generally cycle on and off.  

Quickest way to confirm a wiring issue is just to pull the 5V wire out of the ecu plug, plug ecu back in and switch ign back on.  Then check in the runtimes screen if the 5V output has returned to normal.  If it has then you have something overloading the 5V output. 

The 5V reg that is connected to the outside world is rated at 400mA (enough to power about 50 typical sensors), but they can actually drive more than that - just with reduced accuracy.   They dont shut down until somewhere above 1A, so it usually needs to be a fairly serious short usually to trip it out.  

[Tom H]

Thanks for the reply Adam. 

since writing this about 8 hours ago I did pull the ECU from the car and bench tested it. to do this I connected the 1 x 14v feed, 2 x Grounds on pin 25/34. I also tapped off the 2 sensor grounds pin 7/24 and the +5 out so I could test. every thing else is disconnected. 

On initial power up and inspection the run time from PC link showed exactly the same as what I had seen in the car. 0-5V fluctuation  as well as the intake and coolant temp going all over the place. 

I went to test the actual +5v output with a multimeter and the meter showed 5v. I then checked the run time again and it showed the same as what I had tested. so it appears the ECU is good. 

My only issue is why did the fault continue on initial power up and then come right. Does the +5 need a load to check against first before it will show the correct voltage? based on your statement above this shouldn't be the case? 

another question, How much load can the sensor ground wiring take? I have just noticed that my Innovate grounds through this. this was intentional at the time but probably not ideal is it will be drawing a bit of current I would imagine. its been connected like this for years. 

Thanks 

[Adamw]

15 minutes ago, Tom H said:

On initial power up and inspection the run time from PC link showed exactly the same as what I had seen in the car. 0-5V fluctuation  as well as the intake and coolant temp going all over the place. 

I went to test the actual +5v output with a multimeter and the meter showed 5v. I then checked the run time again and it showed the same as what I had tested. so it appears the ECU is good. 

My only issue is why did the fault continue on initial power up and then come right. Does the +5 need a load to check against first before it will show the correct voltage? based on your statement above this shouldn't be the case? 

I dont have any logic to explain that and it is not behavior I would expect so there could potentially be something failed or a failing solder joint, but you will have to try it back in the car now to see if you have a reproducible problem.  

 

15 minutes ago, Tom H said:

another question, How much load can the sensor ground wiring take? I have just noticed that my Innovate grounds through this. this was intentional at the time but probably not ideal is it will be drawing a bit of current I would imagine. its been connected like this for years. 

Yeah I would suggest moving to ground to the engine block instead.  The current I dont expect would be an issue, but you will be pushing all that wideband heater noise into your sensor ground and it will make all other sensors appear more noisy.

[Tom H]

Thanks Adam, 

I did plug the ECU in last night and then plugged each sensor in one by one and monitored for faults. After plugging every sensor in the +5V remained constant on the run time screen.

I didn't start the car, so I cant confirm the issue has "gone". Ill run the car tonight to see if I can replicate the fault. Then work out options I guess. 

Edit: I have since contact cleaned every sensor and plug, remade wire insulation in some areas, and changed the wiring on the innovate. Took the car for a brief drive and no faults occurred. Sounds promising although this is what had happened previously. Fingers crossed. 

Thanks.