Trouble shooting help, what next, what have I missed.

[headscratching]

I asked Ai to summarise what i have done so that people who dont speak gibberish can help.

Peugeot 208 1.6 BlueHDi – EDC17C60 diagnostic help needed
I'm looking for advice interpreting diagnostic results on a 2016 Peugeot 208 Mk1 1.6 BlueHDi.

The car originally had the 75 hp DV6FE/BHW engine, but now has a replacement 100 hp DV6FD/BHY engine.

Diagnostics were carried out using the automatically identified profile:

Automatically Search → Peugeot 208 → System Selection → Engine ECU → EDC17C60

ECU identification:
Bosch EDC17C60
ECU equipment number: 9806460480
Software reference: 9692540080
Software version: 02.04
Fault codes recorded:
P0403 – EGR valve control circuit open (temporary)
P0406 – EGR valve position voltage too high (permanent)
P1461 – EGR bottom-stop programming discrepancy (temporary)
P0113 – Intake air temperature at airflow sensor, component voltage too high (permanent)

Relevant live data:
EGR position signal voltage: approximately 4.99 V
EGR command: 0%
EGR position: 0%
EGR upper-stop programming: Done
EGR lower-stop programming: Not carried out / unsuccessful
Air mixer position sensor voltage: approximately 0.5 V
Controlled air inlet module: No Movement
Air mixer lower-stop programming: Done
Air mixer upper-stop programming: Invalid value
Four monitored 5 V supply status parameters: No Fault
EGR wiring checks:

With the battery disconnected and ECU unplugged, continuity was checked from all five EGR connector pins to the ECU connector A terminals. All five matched the wiring diagram:

EGR pin 1 → ECU A17
EGR pin 2 → ECU A58
EGR pin 3 → ECU A6
EGR pin 4 → ECU A87
EGR pin 5 → ECU A88

Main symptoms:
Loss of power, rough/lumpy idle, difficult starting, occasional white smoke and unpleasant exhaust smell, particularly under load.

The EGR lower-stop programming repeatedly fails.
Air douser is always whining when ignition is on.

Questions:
What could cause the EGR position feedback to remain around 4.99 V with P0406?
Could this explain the P0403 and failed lower-stop programming?
Could there be an ECU calibration or compatibility issue because the engine has been changed from DV6FE/BHW 75 hp to DV6FD/BHY 100 hp?
What would be the best next diagnostic test to distinguish an EGR actuator/feedback fault from a wiring or ECU fault?
Would the invalid upper position of the air douser affect the EGR lower stop programing causing a failur loop where neither can beprogramed because the others program is invalid.

I'm particularly interested in advice specific to the Bosch EDC17C60 and DV6FD/BHY installation.

Or as a village idiot do I just get a man with a van out to diagnose and fix it. anything to help. Wife is in my ear about useing her car for work.

Regards
Head scratcher.

[mickthemaverick]

Was the EGR swapped with the engine ?

[xantia_v6]

Is the engine swap recent or has it been running for a while with the replacement engine?

[headscratching]

I believ the engine swap may have happened in 2019 while still an unmarked police car, I got it in march 2025.
The only reason for that belief is the 2019 date on the ECU version it i unknown if the EGR was swaped.