BMW LCM, Right hand head light always on



BMW 520 E39 1996


R/h/f  high beam (main beam) light always on

The client had removed the wiring to the R/H/F high beam light as it would drain the power from the vehicles battery and cause it not to start.
After initial consultation we decided to check the system power fuses etc, and check what is at the high beam light connection on the left hand side the was only an earth present, on the right hand side the earth and a power source was present, which explains why the high beam light is on, the circuit is a power switching circuit.

We then consulted a workshop manual to find out more on the head lights, The head lights are controlled by an ECU known as the LCM (light control module), the light modules location is R/H/F kick panel (drivers side in a right hand drive vehicle).

Then it was time to connect the scan tool to the vehicle, the vehicle had an LCM module connected to the vehicle so we decided to connect to that module and check for fault codes, on initial check of the faults codes we had 6 fault codes, the fault codes did not relate to our problem so we decided to clear the fault codes and restart the procedure, once testing the system again we then came up with a fault code 14


By no means could any one understand this, we went back to consult the workshop manual and found that code 14 is an internal ECU fault, which made sense knowing that the power circuit did not switch off as the transistor, and that the transister was not dropping the voltage, even with ignition off.

Once the New LCM has been fitted the LCM must be programmed to the vehicle, The LCM stores the speedo reading in 3 places the DME, Instrument cluster and the LCM, if one of the three does not correspond a red dot on the instrument cluster will be displayed.


written by Mats Isaksson Poweruser on


LCM – Fault Code table



10 Control unit
11 Control unit
12 Control unit
13 Control unit
14 Control unit, microprocessor
15 Control unit, microprocessor
16 Control unit, microprocessor
20` Brake light switch
21 Brake light switch
22 Headlight range control
23 Dimming for interior light
24 Trailer control unit
25 Turn signal switch
30 Head light range control
31 Actuation of servomotor for headlight-level control, Left
32 Actuation of servomotor for headlight-level control, Right
40 Oil Level sensor
50 Terminal 30
51 Terminal R
52 Terminal 15
70 Headlight range control
80 Control unit memory
82 Braking system
83 Engine oil pressure
84 Coolant temperature
85 Catalyst
86 Injection pump
87 Level control
88 Engine management system
89 Transmission control
90 Brake lining wear
91 Windshield washer fluid level sensor
94 RF key
95 Coolant level
96 Engine oil level
97 Tyre pressure
120 Left dipped beam
121 Right dipped beam
122 Front left side light
123 Front right side light
124 Front left turn signal indicator
125 Front right turn signal indicator
126 Right fog light
127 Left reversing light
128 Left main beam
129 Right main beam
140 Left tail light
141 Right tail light
142 Left tail light
143 Right tail light
144 Rear left turn signal indicator
145 Rear right turn signal indicator
146 Brake light, left
147 Brake light, right
148 Rear left fog light
149 Rear right fog light
150 Left reversing light
151 Right reversing light
152 Centre brake light
153 Licence plate light
E587 CAN Controller
E588 CAN Controller
E58b CAN Controller