Just driving home from work tonight when the yellow service light came on and I received a Powertrain Malfunction / Reduced Power message on my FordPass app. However when I connected my phone to the OBD port there were no faults logged and when I turned the engine off and on again, the service light went out. Unfortunately having restarted the car and carried on with the journey, the same light and message came up twice more and disappeared each time with a restart. I've had no problems leading up to this - any suggestions? (2018 Mk4 Focus, 1.0 123hp petrol)

Are you using the software FORScan to read the DTC's ?

8 minutes ago, unofix said:

Are you using the software FORScan to read the DTC's ?

Yes, the "lite"/mobile version. Also tried FordSys Lite. Can see everything else is fine but no DTCs are logged (which is why the light goes out when powered off and on again I suppose).

You will have to try and read the DTC's while the engine management light is still on.

Is your car an automatic ?

7 minutes ago, unofix said:

You will have to try and read the DTC's while the engine management light is still on.

Is your car an automatic ?

No it's manual. Even when powered on with the service light showing, no DTCs are logged. On getting home, I've re-filled with a tank full of petrol in case there's some weird contamination in the fuel which is causing momentary "hiccups".

You need to use the full version of FORScan on a laptop. It is just not possible for the engine management light to be on and there to be no DTC present at the time of checking. The light can only be turned on by an active DTC, which in your case seems to clear each time the ignition is cycled.

The code is going to be a specific Ford only DTC and is not been seen by the mobile version, probably because the bluetooth OBDII dongle is not seeing the problem.

Windows version of FORScan: https://forscan.org/download.html

vLinker FS lead: https://www.amazon.co.uk/Vgate-vLinker-Adapter-FORScan-MS-CAN/dp/B0952P4MLP/ref=sr_1_2?crid=8ESM5DDDYGAL&keywords=vlinker+fs&qid=1651603065&sprefix=vlinker%2Caps%2C131&sr=8-2

All seems well today - no service lights, no loss of power. I'll keep my fingers crossed that it was just a momentary hiccup.

I had this problem a while back with similar warnings coming on Ford Pass App. I contacted the dealer who remotely read the app warnings and advised it was due to low charge on battery. I put battery on charge for 12 hours reset BMS and touch wood it's never happened again. Hope this helps should your problem return.

On 5/5/2022 at 8:53 AM, boristhebold said:

I had this problem a while back with similar warnings coming on Ford Pass App. I contacted the dealer who remotely read the app warnings and advised it was due to low charge on battery. I put battery on charge for 12 hours reset BMS and touch wood it's never happened again. Hope this helps should your problem return.

Thanks, been a few days now and no more lights- fingers crossed whatever it was has worked its way out. If it happens again, I'll give the battery a charge.

Hi all I’ve had this issue with my 2021 ford transit custom L300 L3 LWB Euroblu had it at ford couldn’t find a code ….

i figured out it’s when I’m driving in to high a gear and revs are to low the minute I down shift and revs go up it gives off after 3-4 miles it happened more in cruise control told ford and they reported it and said there should be an update issued to address it but never had it in 18 months