Failure phenomenon: a 2002 annual Dongfeng Citroen Picasso 2.0 L sedan, mileage 100,000 km. Say users, the car left rear tail light does not shine.
FIG 1
Check Analysis: fault validation, found to open the left rear position light a small lamp and left front position light is off, the instrument Night It does not light. A plurality of light does not shine fault common fuse is blown, fuse box BH12 cockpit check the fuse F34 (10 A) fuse. Replacement of the fuse, as long as the opening a small lamp, immediately blown fuse, the fuse F34 which shows a control circuit of a short circuit member or place. Left front position lamp turn OFF, the left rear position lamp and instrument, but the short-circuit fault is still present. In the absence of a circuit diagram, the user’s manual that fuse F34 includes a left front position lamp control section, a left rear position lamp, the meter – the parking ignition – Run, to be understood that for the first three, and ignition – what function operation means or member bad understand. A circuit diagram of the lamp from the Internet to find the location of the vehicle (Fig 1), show a circuit diagram of a fuse F34 in addition to controlling the left front and the left rear position lamp, but also via the intelligent control box BSI1 a license lamp power. Remove the instrument panel trim removed BSI1 lower left, found a lead wire out from the BSI1, apart BSI1 plastic housing, found a pin break, the broken line is the pin solder tails. It was measured, and the next one line through the guide pin. This is not because of welding two pins shorted it? The lead solder off, measure the feet and the next stitch is turned on, it appears that originally turned on. Re-weld wire, and a fuse F34 BSI1 refitted, this time to open when the fuse not blown small lamp, is repeatedly opened and not blown. This is strange! With luck all the removed parts refitted, refitted and then open a small lamp, the fuse will blow up.
off again left front position lamp, rear left position lights, license plate lamp and the meter until the fuse is disconnected BSI1 not blown, or appears to be BSI1 BSI1 license plate lamp control line in question. From the view of a circuit diagram of a conventional fuse F34 BSI1 control member via a meter and a rear license plate lamps, BSI1 and instrument are connected via a communication line, the communication line if a short circuit case, each control unit is not in communication. The car just blown fuse without the phenomenon of communication failure, soBSI1 can rule out the possibility of short-circuit line to the instrument, only after checking BSI1 license light line. 16V VE current through the plug into the fuse F34 BSI1, 16V NR output from the plug. After measuring plug 16V NR line leading to the license plate light, no short circuit condition, when the fuse F34 is inserted into a small opening light not blown. Why sometimes no fault could it? Then refitted BSI1 individually access the electrical equipment, when the left mounting dashboard trim, and the fuse F34 blown. It seems related to the failure of this component. Five switches (FIG. 2) on the trim panel, left and right rear lifter switches, meters, switches brightness adjustment, height adjustment headlight switch and an electric mirror adjustment switch, just after the fuse F34 is connected to an electric when the mirror switch harness fuse, it seems finally found the point of failure, the switch is caused by an internal short circuit.
FIG. 2
After that communicate with users, recent electric mirror switch is broken, the small repair shop for a new one, because it was during the day, so do not try lighting. According to remind yourself, when was the replacement and installation of switch mount some wrong slot, the maintenance staff can put something that has since stumbled on the left rear tail light at night does not shine, it seems that nocturnal lighting inside the switch gear short circuit.
troubleshooting: Because users do not want to spend money to replace the switch, then the switch socket of nocturnal illumination power pin stripped out with insulating tape wrap, no problem occurs after test refitted.
reviewed: According to my observation, car repair shop in other power mirror switches are replaced with Elysee car, as long as the protrusion guide groove on the switch can be installed to remove the vehicle Picasso but this installation can cause short circuits. I later met Picasso Case wrong equipment Elysee headlight switch one case, users reflect the headlights are always blow deformed, even within a month for a four headlights, after communicating with the user judged ago lamps switch wrong type, examination revealed a headlamp switch for the user to replace Elysee models, can be installed without modification on Picasso. Elysee dual lamp system is a headlamp (distance light using two different lamps, light near the opening when a low beam light bulb, the opening distance light beam when the light bulbs), Picasso single lamp system (light with the same distance a light bulb, light is near the openingBright low beam filament, the high beam filament when Kaiyuan bright light), the erroneous mounting, when the user regarding the opening distance light beam lights are lit, lamp heating is too large, the user often traveling at night, resulting in serious heat deformed headlamp .
to replace the wrong car power mirror switch, the first maintenance staff did not actively communicate with the user in troubleshooting process, leading to the investigation process a few detours. Second, there is no original circuit diagram of a circuit diagram of the Internet found incomplete, resulting in a current fuse F34 unaware reached by BSI1 power mirror switch. Third, the maintenance personnel in the repair process did not notice the missing power mirror switch nocturnal lighting function, otherwise early detection point of failure. 4S shop for the car’s fault, because there is the original circuit diagrams, so the chance of false positives is relatively small, for non-4S shop for this failure should be noted.
(Dulei Lei)