ForScan freezes on live data when engine started

Discussion about adapters and connections - usage, problems, solutions
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jamesmurphy09
Posts: 2
Joined: Tue Nov 03, 2020 9:42 pm
Vehicle: mondeo, diesel, 2.0 L, 140bhp,

ForScan freezes on live data when engine started

Post by jamesmurphy09 »

Hello there. Hope someone can help. My problem is that ForScan works fine on all functions, including live data, as long as the engine is not running. As soon as I turn the key to start the engine, the timer at the bottom of the 'Read PID data' screen stops and ForScan freezes. In the 'Vehicle and interface information' panel both connect and disconnect buttons are disabled. Then I get two error popups saying 'Unable to run data stream. Make sure the Ignition key is on and try again', and 'No adapter found. Please check connection and try again'.

My adapter is an original OHP USB adapter with HS/MS switch and I am running ForScan 2.3.40 on Windows 10.
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fordsmax471
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Joined: Mon Aug 07, 2017 5:29 pm
Vehicle: Ford S-Max 2.0 TDCi 2017 PowerShift

Re: ForScan freezes on live data when engine started

Post by fordsmax471 »

original OHP USB adapter with HS/MS switch :D :D :D
FORScan 2.4.3/UCDS 4/Elitebook G6/Win10 pro
tractmec
Posts: 431
Joined: Thu May 26, 2016 11:43 pm
Vehicle: F150 5.4 Triton 2005 Expy5.4 2003 Fusion 3.0 2010

Re: ForScan freezes on live data when engine started

Post by tractmec »

jamesmurphy09 wrote:
Sat May 08, 2021 2:34 pm
Hello there. Hope someone can help. My problem is that ForScan works fine on all functions, including live data, as long as the engine is not running. As soon as I turn the key to start the engine, the timer at the bottom of the 'Read PID data' screen stops and ForScan freezes. In the 'Vehicle and interface information' panel both connect and disconnect buttons are disabled. Then I get two error popups saying 'Unable to run data stream. Make sure the Ignition key is on and try again', and 'No adapter found. Please check connection and try again'.

My adapter is an original OHP USB adapter with HS/MS switch and I am running ForScan 2.3.40 on Windows 10.
Common problem! This can happen, especially if your battery is near the end of it's life span or you have been running "Live Data" for quite some time and system voltage has been pulled low. This will very often throw some low voltage codes in several modules!

Older and many Chinese built ELM327 adapters also were very often sensitive to voltage fluctuations on the number 16 Pin in the DLC connector as that is where the adapter connection is partially powered!

If starting the engine while connected pulls the voltage on pin 16 below 12 volts which can very easily happen given the above conditions, the connection to the car and to the computer can be completely disrupted and the only way to reconnect is to completely disconnect all cables and then reconnect and start another session with the engine running. Newer non clone ELM327 adapters and especially J2534 Passthru adapters have bigger Capacitors to store current that mediates this condition.

Putting a charger on the battery to help keep system voltage up, while doing these kind of procedures is very helpful and actually should be done for anything other than doing a quick DTC code read! Having the laptop plugged in to power also helps!

Hope this helps!
jamesmurphy09
Posts: 2
Joined: Tue Nov 03, 2020 9:42 pm
Vehicle: mondeo, diesel, 2.0 L, 140bhp,

Re: ForScan freezes on live data when engine started

Post by jamesmurphy09 »

Cheers mate. Thanks a lot. I did suspect it may be the battery, as this never happened before my Ford battery went on me and I put an Exide from my old Rover in. I have also been getting DTC's that are mentioning voltage below threshold. Think I will have to get another battery.

Cheers again.
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