[Slizza786]

Hi,

I have a 2007 bmw e93 330d (produced Jul2007) and my instrument cluster is completely dead. It has 0 power with nothing working. The rest of the car is working fine i.e external lights, OBD port, interior lights, climate controls etc.

I have checked the fuse and it was not burnt but also for my car, the cluster uses the same fuse as the OBD and that was working fine. I disconnected and reconnected the cluster with both with ignition on and off but still no luck. I disconnected the battery for 30 minutes and nothing was seen.

Before I go send my cluster off for repair (which seems quite expensive) I wanted to see if the cluster itself is working or not. From the researching online, I understand that pin 9 is live and 18 is ground so was planning to connect the cluster to a 12v and see if there's any life in it. I was also planning to do a continuity test on the X1175 connector between 9 and 18 to see if there is a solid connection.

Before I attempt to test the cluster with the 12v, I was told that there would be no power whilst testing as the cluster needs the 'wake up line' as well as power in order to show some life - is this true and can I not test the cluster with just pin 9 and 18?

Haven't been able to try as not next to the car right now so was hoping to find out if anyone else managed to test their cluster whilst it's off the car and how they went ahead and did that.

I'm quite new to electronics so apologies if I sound stupid.

[Slizza786]

Tried a continuity test on the cluster against pins 9 and 18 but there was no change however when I touched 9 and 14 together, my multimeter showed some change in value. I just feel soo confused right now.

[LMB335IS]

Connect the 9 and 18 pins like you outlined. You should see the needles move up and down a small amount as the stepper motors zero and the lcd screen should light up if you press the trip odometer reset button.

[gbalthrop]

I'm NOT an electronics expert either, but I would test things the "other way around", testing for 12V+ (both ignition OFF and Ignition ON) at Socket #9, Red Wire, of KOMBI (Instrument Cluster) Connector X11175; THEN I would test for Continuity to Chassis Ground (BOTH Ignition OFF & Ignition ON) at Socket #18, Brown/Black wire, of X11175.

My SWAG is that you MAY have either a bad ground supply or bad B+ supply to the Instrument Cluster (A2a in Schematic). I attach (To NEXT Post) an ISTA ScreenPrint for A2a wiring diagram (SSP) and Connector View of its Connector X11175. Also attached will be Connector Location and Connector View of X14272 at the JBE Module (below JB Fuse Panel).

There are FOUR critical wires related to Instrument Cluster Operation, and ALL of them are connected to the JBE, X14272, as shown in the first attachment:
1) Red (RT) B+ wire from X11175/9 (Pin#9 of A2a Connector X11175) to X14272/3 at JBE;
2) Brown/Black switched ground wire from X11175/18 to X14272/9;
3) Orange/Green K-CAN High from X11175/6 to X14272/29;
4) Green K-CAN Low from X11175/7 to X14272/31;

Of course for ANY electrical CIRCUIT, the Ground connection (to 'send the electrons BACK TO the battery ;-) is of equal importance to the B+ connection which 'receives electrons FROM the battery'. If a connection in EITHER part of the circuit is corroded or "open", NO (adequate) current flow occurs. Any cheap Multimeter will allow you to test for Voltage and Continuity to Ground (Ohms Resistance ~ 0).

Where the wheels come off for most of us is understanding the BUS connections (K-CAN or Body Bus). Think of the ~ 20 different "Modules" in your vehicle as computers on a network, and the JBE module as the "Router" or Network HUB/Gateway. The Instrument Cluster does NOT use discreet wires for each warning light, gauge, etc., but rather uses signals between the Modules on the BUS, similar to computers sending data or messages to each other in both directions on a "Cat 5" Cable on "wired" network.

If the Wire is unplugged or not properly connected, NO messages flow. So I would unplug X14272 at the JBE and make sure you have continuity between both ends of each: (i) the Orange/Green wire, AND (ii) the Green wire, between X11175 & X14272.

In your case, if NOTHING on the Instrument Cluster ever lights up, my SWAG would be you have a B+ or Ground issue as opposed to K-CAN bus issue. If you had INPA, ISTA, or a Scan Tool that can read Faults and Live Data from ALL Modules, we could learn MORE.

So for starters, test the Vehicle side of Connector X11175 as described above, and let us know what you find.

George

[gbalthrop]

Attached are ISTA wiring diagrams, Installation Locations & Connector views as described in detail in prior post.

George