I have a megane 1997, K7M motor, AD4 A/T.
It has been acting up lately with several weird symptoms, eventually traced down to an intermittent A/T control solenoid (Electro-pilots as they're named by Renault), from now on I'll call them gear selecting solenoids (GSS).
The problem is that this solenoid comes as part of a harness including 4 GSS's, 1 pressure modulating valve (PMV), and a temp sensor, all amounting to big $$$$$ (to be specific, over 1000 including work...Guests cannot see images in the messages. Please register to forum by clicking here to see images.
To avoid the hefty cost my gear specialist installed a GSS from a DPO A/T (also called AL4 in Peugeot-Citroen). They look physically the same, but the DPO solenoids can be bought in single units much cheaper (1/16 the cost!) and soldered into the old harness (the DPO harness is modular and has connectors for each, as opposed to AD4 which is one-piece).
I've measured and compared resistance readings of both GSS's (DPO snd AD4) and they seem very similar also electrically (30ohms AD4 vs 40ohms DPO), and moreover, the new DPO solenoid works just fine in my AD4. On the other hand, I've read in various places that not all solenoids from both A/T systems are compatible, e.g. the PMV's are not, because they are designed for different pulse widths. I've even found that even **within the DPO line** there was a change of pressure modulating valves during production life, that requires ECU reprogramming for the newer units if installed. *copy righted material removed
Analysing the doc, it seems that they're talking about two PSV's (one for A/T system pressure control and the other for torque converted locking mechanism not present in AD4) and not the gear selecting ones. As far as I could understand, the PRV's are pulse-width-modulated by the A/T ECU at high speed to to regulate the required A/T pressure based on the external pressure sensor output, hence must act very fast. On the other hand, the GSS's change only at gear shifts and are otherwise static.
Has anyone tried and can confirm that DPO GSS's are indeed compatible with AD4 in the long run?