Diff warning light question

Steve Brookes · Nov 29, 2008

I received this question from a C4 owner. Can anyone help?

If i start it 1st thing in the morning the diff light and ! light stays on for a bout 15-20 seconds then a bleeping noise comes from the dash and the lights then go out. Is this normal or it it linked to the 4wd system not working?

Dave Wilkinson · Nov 29, 2008

Steve,

It's linked to the fact that the driver is in too much of a hurry to experience the C4!! Because the C4 has the high pressure hydraulics there is a pump which runs as soon as the ignition is turned on which generates the pressure in the brake system. Once the pressure reaches it's working level the pump stops. As pressure is used the pump will spark into action for a few seconds at a time throughout a journey.

The problem that's being experienced is caused by driving off before the pump has built up sufficient pressure. The PDAS system sees the movement of the wheels and highlights the potential problem of NO BRAKES and reasonably enough warns you.

If you have a little patience and wait for the pump to stop before you drive off you will never see the warning lights again.

It's all perfectly normal stuff - just needs patience!!!

Regards

Dave

Steve Brookes · Nov 29, 2008

Thanks Dave, I'll pass that on.

tony`mac · Nov 30, 2008

ORIGINAL: brksy16

I received this question from a C4 owner. Can anyone help?

If i start it 1st thing in the morning the diff light and ! light stays on for a bout 15-20 seconds then a bleeping noise comes from the dash and the lights then go out. Is this normal or it it linked to the 4wd system not working?

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Just out of interest Steve, what is the beep that comes from the dash shortly after starting ??

Steve Brookes · Nov 30, 2008

ORIGINAL: tony`mac

ORIGINAL: brksy16

I received this question from a C4 owner. Can anyone help?

If i start it 1st thing in the morning the diff light and ! light stays on for a bout 15-20 seconds then a bleeping noise comes from the dash and the lights then go out. Is this normal or it it linked to the 4wd system not working?

Click to expand...

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Just out of interest Steve, what is the beep that comes from the dash shortly after starting ??

I don't get the beep because I have no warnings on starting - the question above was from someone else with a C4. Do you get a beep AND the exclamation warning light?