Handbrake warning light

You were kind enough to offer some suggestions about the faulty steering warning message on my 2008 Ford C-MAX 1.8 Zetec petrol. For months now, I have had another intermittent warning light for the handbrake/low brake fluid. The garage has suggested the GEM module may be at fault. I didn’t know what this was, but have discovered that it is alarmingly expensive. Unfortunately, the carefully worded warranty does not cover this particular item. Andrew Webb

I am assuming that you have a conventional handbrake and not the electric version. From the data I have, I think it is unlikely that the GEM module is the source of the warning light. There are four possibilities and I would systematically work through each of these.

The first is that the brake fluid level is low or that the level indicator is faulty. As you have had the vehicle checked by a garage, we can hopefully assume that the fluid level is not low, but the continuity of the level sensor should be checked.

The second possibility is that the handbrake is not properly adjusted and is not sitting fully on the warning light switch. Again, I would have expected this to have been detected by the garage, but the switch itself should be checked using a continuity tester to ensure it is operating.

The third possibility is that a short has occurred somewhere in the loom. This will involve methodical testing of the wiring circuit. One point to check – as highlighted by Autodata – is the fascia fusebox/relay plate harness and multi-plugs. Damage can occur here due to water ingress from condensation coming off the AC evaporator pipes.

The final possibility is that the fault is within the ABS system. In some circumstances, errors in the ABS will illuminate the red warning and not the orange ABS warning light. Problems within the ABS system should be detectable using a Ford diagnostic system connected via the EOBD socket.