Aftermarket June 2023

JUNE 2023 AFTERMARKET 27 intermittent SRS fault indicated as drivers squib circuit. I also noted that the cruise control switch was not operating. I cleared all codes and advised a second opportunity to confirm if it reoccurred which it did. Pretty straightforward advice and choice here; It was the clock spring. Due to impossible test opportunities in service, a new unit was recommended. Swapping out all the trim exposed the possible cause of failure; Extensive cigarette ash within the steering housing. There are several electrical sockets within the housing controlling most of the lights, wipers, cruise control. These were electrical lube-cleaned and complimented with a new clock spring. Fault fixed. This was shortly followed with a battery charging fault. The vehicle would charge normally for a brief period then the generator light would illuminate. The wipers would then operate without request and could not be terminated until the ignition was switched off. As I only work three days per week (perks of seniority, in every sense), a new alternator had been fitted by the shop with no change in status. The Renault employs smart charging technology, so my focus started right there. Smart charge systems rely on digital alternator exciter control. This was not present when scoped, only a flat 10v reference was present. Challenge Fault codes confirmed the area of responsibility, df002, alternator control unit, df003 main system voltage, df0047 battery sensor voltage value out of range. Additional serial data indicated a starter relay, and wiper stalk fault. My next challenge, wiring schematics. E3 did support the system schematics, so off we went. Pin ID references did not check out, however wiring colour did seem to be accurate. Please refer to Fig.1. I chose to disconnect the battery sensor and E6, the battery supply control unit, then conduct continuity tests through the loom. My first test points were at each extreme of the battery sensor circuit. Result open. Next, I broke down the circuit, from the battery sensor to a connector under the dash on the nearside. Result; 2 ohms, so ok. Please refer to Fig.2. From the exit of the socket to battery sensor, result open, so the connector was faulty. I then chose to construct a simple bridge circuit to bypass the socket. Result; Smart charge control back online. So, the alternator puts out the 10v. This is modified to a digital charge control signal within the power supply module, thus proving a good module. The connector is quite a high-tech design, and relies on a mechanical zero stress engagement principle. The pins are incredibly small and fragile, so my only option was to cut the circuit on entry and exit then solder together. The alternator now charges normally, the wipers operated normally when requested via the control stalk, and all DTCs cleared. Please refer to Fig.3. Soft master vs. hard master So, what was my performance assessment? I’m a hard master, but pragmatic enough to identify where the problems existed. There was not quite enough data on E3, but a little visual assistance from the Google wizard to identify the various modules helped. Try eBay for secondhand units. You will get quite clear photos to assist location and identification. See, I’m a softie when it comes to helping you lot. More next issue. Fig. 2 Fig. 3

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