Note: Whenever a new ECU is fitted, the unit must be initialised using Peugeot diagnostic equipment before the transmission will function. If the following procedures are being undertaken with the intention of ECU renewal, this work should be entrusted to a Peugeot dealer.
General
1. The transmission electronic control components described in this Section consist of the electronic control unit (ECU), a multifunction switch and a speed sensor. The multi-function switch and speed sensor are connected to the ECU by an integral wiring harness and the three components therefore form one assembly. The multi-function switch and speed sensor are located on the transmission assembly, while the ECU is mounted above the transmission, adjacent to the battery on early models and in front of the transmission on later models.
Removal
2. Disconnect the battery negative terminal (refer to "Disconnecting the battery").
3. Where the ECU is mounted above the transmission, remove the air cleaner assembly and intake duct as described in the relevant Part of Chapter 4 and the battery as described in Chapter 5A.
4. Remove the ECU cover (where applicable) and remove any cable ties from the wiring harness in the vicinity of the ECU wiring connector. Disconnect the wiring connector, remove the retaining strap and withdraw the ECU from its location. Disconnect the remaining connectors from the base of the unit (see illustration).
7.4. ECU retaining strap (1) and mounting components
5. Trace the wiring harness to the speed sensor and multi-function switch and make notes of the harness routing for refitting. Release any cable ties or clips encountered.
6. Undo the retaining bolt and earth lead bolt and withdraw the multi-function switch from the transmission (see illustration). Recover the switch O-ring.
7.6. Multi-function switch (3) location on the transmission
7. Undo the wiring harness clamp retaining bolt and the speed sensor mounting bolt and withdraw the speed sensor from the transmission (see illustration). Recover the O-ring.
7.7. Speed sensor wiring harness clamp (4) and speed sensor (5)
8. Carefully feed the components and cables out from their locations and remove them from the transmission.
Refitting
9. Refitting is a reversal of removal noting the following points:
- a) Use a new O-ring on the speed sensor and multi-function switch.
- b) Ensure that the wiring is routed and correctly clipped back into place as noted during removal.
- c) Refit all remaining components disturbed during removal.
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