On Ford diesels with a Bosch VP30 or VP44 pump — Focus 1.8 TDDi, Transit and Transit Connect TDDi — the pump’s PSG5 control unit is part of the vehicle’s immobiliser system. A locked control unit prevents the engine from starting in exactly the same way as a faulty one, so the two cases should be told apart before any part is replaced.
Pairing with the immobiliser
The pump control unit and the engine control unit recognise each other within the Ford immobiliser. Only when the pairing is correct does the pump control unit allow the engine to start.
Reading the red warning light
The pairing status is shown by the red warning light on the centre console when the ignition is switched on:
| Warning light at ignition on | Meaning |
|---|---|
| Lights briefly, then goes out | Pairing correct; immobiliser operational. |
| Stays on or flashes | Pump control unit locked; the engine will not start. |
A locked unit is not a faulty unit
A locked control unit may be in perfect working order. This is the usual situation when a pump or control unit from another vehicle has been fitted. Unlocking can be carried out at an authorised Ford dealer or with the HC-VCI diagnostic interface, which includes the unlock function for Ford pumps with a PSG5 control unit.
The common case of a pump from another vehicle: A VP30 or VP44 pump from another Ford: immobiliser lock and how to resolve it.
Replacement with HC-PSG5
HC-PSG5 units for Ford applications do not lock. Fitting them requires no pairing or unlocking procedure: they are supplied coded and calibrated for the pump number and connect to the original connector.
Recommended diagnostic sequence
- Observe the red warning light when switching the ignition on.
- If it stays on or flashes, read the pump’s identification and fault codes.
- If the control unit is locked but sound, unlock it.
- If the control unit is faulty, replace it with the HC-PSG5 that matches the pump’s Bosch number.
References: HC-PSG5 compatibility and references. Enquiries: contact.
Herlic Components — OEM-equivalent diesel injection electronics, engineered in Europe.
