Diagnostics Doctor

FORD S-MAX

Intermittent starting issue

Q There is an intermittent non-starting issue when the keyless start button is pressed on my 2011 Ford S-MAX 2-litre diesel–nothing happens! There is also occasionally a MIL and “Engine Malfunction” message appearing on the dashboard but no-fault codes showing when I carry out an OBD check.

I have checked all fuses, relays, the keyless start button connections at the PCM (ECU) and most of the wiring but now suspect the PCM (ECU) may be holding the start off for some reason?

As a temporary measure I have installed a start button that takes live from the battery and puts it straight on to the starter motor solenoid and then with the keyless start button turned on (ignition on), the engine starts and runs with no issues.

I have done numerous OBD checks using an Autel MaxiSys MS906BT and, after clearing all errors and road-testing, no errors show–but the Engine Malfunction message will still sometimes re-appear. This, like the keyless start button issue, is very intermittent.

I have checked the keyless start button and the wiring