high beam not staying on

[weetabixface]

Hi all

2008 9-5 aero estate

high beam will not stay on, I can flash and keep high beam on if I hold the indicator stalk pulled up toward the steering wheel but goes off as soon as it is released, related fuses all look fine, I guess relays are the next place to look/swap out

any suggestions appreciated

W

[sgould]

It'a over four years ago that I dismantled my lighting stalk.  And I think that the latching is done mechanically inside the switch.  Not 100% sure that I've remembered correctly, but the relays are not latching ones.

[phoenix]

There's two active connections from the stalk dip switch. One, via DICE, does the latching main beam (Pin 6) via the main beam relay (position 8a) The other supplies 12V directly to the lamp (albeit via the filament monitor) for the flash function (Pin 1).

So yes, the main beam relay is a good place to start.

[weetabixface]

dipped and high beam relays are the same part #, swapped them over, dipped beam is still functioning fine and main beam still giving the same problem,

with the relay in place, when the high beam function of the stalk is operated can hear the clunk as it closes and immediately opens again

with the relays removed, and operating the switches, dipped beam relay is reading 11.5V and high beam relay is @ 10.5V when energised and staying at that till the stalk is pulled again to switch off, guess I need to dig a little deeper

[phoenix]

I'd go for the filament monitor relay next (the orange one). Re- flow the solder joints for the pins.

[weetabixface]

no orange relay and no connections at FR1 to take a relay

[phoenix]

Duh. Forgot it was xenon that doesn't have the filament monitor relay.

The operation is:

Flash- fed direct from the column switch via fuses 7 & 12.
Latch- DICE energises the relay, (pull to ground). The feed to the main beam relay (load and coil) comes from the dipped beam relay So from the attached, it's a problem with the feed from the DICE unit.

You will see the feed from the column switch at the output of the main beam relay when you operate the flash. 10.5V is probably not wide of the mark allowing for current induced voltage drop.

So it's either the signal to or from the DICE.
To eliminate a faulty stalk signal to the DICE, apply 12V to pin 6 of the stalk switch.

WIS description:
Main beam is turned on by moving the dipswitch on the steering column towards the steering wheel rim when the light switch is in position 2 and the ignition is ON. DICE activates the main beam relay (8a).

To enable DICE to determine what position (0-1-2) the light switch (10) is set to, the control module uses bus information from TWICE and its own pins 39 and 15.

TWICE monitors the parking lights and sends information on the bus (Rear light Left ON/OFF and Rear light Right ON/OFF). The ON message corresponds to switch position 1 and the OFF message corresponds to position 0 or 2.

To enable DICE to determine the position setting, it uses pins 39 and 15. DICE pin 39 is connected to light switch pin 10, which corresponds to position 0. DICE pin 15 is connected to light switch pin 11, which corresponds to position 2.

B+ voltage is supplied from connection 11 on the light switch (10) to control module pin 15.

When the switch (215) is turned on, B+ voltage is fed from pin 6 to DICE pin 41. DICE lights main beam by control module pin 11 grounding pin 5 of the main beam relay (8a).
When the relay is activated, B+ voltage is fed via the relay to fuse 12 and on to pin 2 of the right-hand headlamp and via pin 10 to pin 2 of the left-hand headlamp.

MIU (540) is powered from fuse 10 so that a lamp 47g on MIU comes on to indicate that the main beam is on.

Diagnostic trouble code B2280 is generated in the event of an open circuit or a short circuit to ground in the main-beam relay circuit. DTCs are not generated if the voltage is below 11 V and the diagnostic communication is in use.

The headlamp flasher turns on the halogen lamp when the lights are switched off. With the lights switched on, the halogen lamp will come on together with the xenon lamp.

When the switch (215) is moved to its “spring-back” position when the lights off, voltage will be fed to pin 2 of the headlamps (663FL/663FR) via fuse 7.

When the switch (215) is moved to its “spring-back” position with the lights on, voltage will be applied to the headlamp (663FL/663FR) pin 2 via fuse 7.

[phoenix]

Diagram

[weetabixface]

wow, thanks for all of that

will take a poke around tomorrow, in between the showers that are forecast

is there a easy way of accessing the underside of the relay box to check connections, cabling etc.?

W

[weetabixface]

this is getting infuriating

relay is fine: checked by energising coil direct from battery, swapped with dipped beam relay and dipped works fine, high beam still not staying on

with relay removed, pull stalk for high beam, voltage to switch relay can be measured with voltmeter, and is there until the stalk is pulled again, removed stalk and operated using a jumper wire, tapping to connect pin 5 to pin 6, with relay removed same response as when stalk is in place - tap to switch shows the voltage, tap again voltage drops

all fuses are fine and there is continuity from the relay, via the correct fuses to pin 2 on each headlamp

opcom reader not currently showing any codes, there is a local guy with Tech2 so will get him to take a look

[sgould]

The more I look at that diagram, the more confused I get!!   I think the only thing left is for you to check the input and output of the DICE unit (628).

[weetabixface]

Just circling back on this in case it helps someone else. Problem was connection between DICE pin 11 & pin 2 on relay 8a, refer to circuit schematic in previous post. Tested with jumper cable between the two points and then wired in, routed through the bulkhead/firewall via the grommet behind the glove box. Weird thing is no trouble codes were showing

Cheers all

W