VOLVO
CEM-8A24 - Gas discharge lamp module (GDL) left-hand. Faulty signal
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (4)
What does this fault code mean?
Although the code is named faulty signal, the left-hand gas discharge lamp module (GDL) reports an internal fault to the central electronic module (CEM). The fault may lie in the module, in the lamp housing or in the signal wiring between them. Check the lamp and the wiring before the module is replaced.
Possible causes
- The left-hand gas discharge lamp module (GDL) is faulty
- The left-hand lamp housing is faulty
- Open circuit in the signal wire between the left-hand lamp housing and the gas discharge lamp module
- The signal wire between the lamp housing and the module is short-circuited to battery voltage
- The signal wire between the lamp housing and the module is short-circuited to ground
What you can do
- 1Switch on the low beam and see whether the left lamp lights. If it does not, check the bulb first and replace it with a new one of the correct type
- 2Switch the ignition off and unplug the connectors to the headlamp. Check that they are not oxidised, loose or damaged
- 3Use a multimeter to check that the signal wires between the lamp housing and the module are not broken and have no contact with ground or battery voltage
- 4After recent removal or replacement, make sure the igniter sits properly. It works on high voltage, so leave other work to a workshop
- 5If the fault remains, have a workshop replace the module. After replacement the car data must be programmed in and the position sensors recalibrated
Symptoms you may notice1
- The low beam does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.