E30 318i: Speedometer / Odometer faults + check list

If your E30 speedometer is broken, your odometer isn't turning or both, then here is a troubleshoot check list to find and fix the fault. Doing the work yourself is a bit fiddly, but totally doable if you are handy with a soldering-iron.

** A more detailed guide / thread all about E30 speedometer / odometer faults by 03IRM3 on r3vLimited.com is here - https://www.r3vlimited.com/board/forum/e30-technical-forums/general-technical/59019-e30-speedometer-repairs-failure-modes, which was a great help. **

NOTE: If your speedometer is not reading, before starting to diagnose the instrument the first thing to check should be if there is a pulse being generated by the speed-sensor in the differential, see E30Zone Wiki here.

Broken Odometer drive gear.

This is the most common problem when the odometer has stopped turning. The drive gear from the stepper motor that turns the larger cogs tends to split on higher mileage cars causing it to skip teeth and not turn the odometer gearing. Replacement gear sets can be bought from eBay for a few quid.

Burnt out resistor.

This is the main power resistor on the 12v + input to the PCB and it's never usually failure of this component that causes it to burn out. Instead, failure of a component further upstream is usually the culprit by drawing way too much current, causing the resistor to work double-time and overheat. This one was still working amazingly, given the heat it had been producing that charred everything around it, but I threw a new one in anyway. The value was about 150 ohms, so that's what I went with.

Blown capacitor.

Sudden failure of both speedo and odometer can often be down to the main power capacitor blowing. This is visible in the above pic to the right of (and next in sequence to) the burnt out resistor. It's a basic 220uF electrolytic capacitor and is very simple to replace with only two pins needing de-soldering, so should be the first step in troubleshooting a dead unit, even if the cap itself doesn't appear blown. Mine had been scorched by the overheating resistor, but seemed ok. I replaced it anyway, but it did not help with mine.

Snapped wire on Odometer stepper-motor coil.

This is rare, but does happen as 03IRM3 has seen one and mine had this too so I guess it does happen, where one of the single strands of copper coil for the stepper-motor snaps off its pin on the PCB. It’s possible that this happens due to time/age and vibration in the vehicle, but could likely be due to manhandling the unit while it is out for other repair work. Either way, it’s an easy fix to just solder it back in place and will be stronger than it was before at least.

UAF chip blown.

If none of the above fixes have worked and both speedo and odo are still not working, the likely culprit is that the UAF I/C chip has malfunctioned and is not processing inputs and outputs correctly, which leads to the resistor burning out, caps blowing and the odometer coil overheating. These UAF2115 chips are common, used in many speedo/odo units, taxi-meters, tachographs etc., so replacements can be found on eBay or electronic component sites for a few £/$, but this is probably the most advanced fix needed for these units and the question at this point is whether it's worthwhile. 03IRM3 has replaced chips as a last resort only to find the unit still won't work, so I decided that with all other fixes not working and my odometer still needing new drive gears that it was time to junk it and seek a replacement unit... [THIS POST].

F10: Clutch Pedal-Pin Repair / Replacement [E60, E90, E92, F01 etc.]

SYMPTOMS:

• Clutch pedal appears to collapse / become loose / twist to one side suddenly when depressed.
• Clutch pedal feels loose / collapsed and will not depress properly.
• Engine will not start and dash displays 'Depress Clutch to Start Engine' message while clutch is depressed.
• Gears will not engage or only partially engage while clutch pedal is depressed.

CAUSE:

Heavy clutch use / clutch-wear causes undue stress to the pedal-box [2 in diagram] and causes the plastic pedal-pin [8 in diagram] to snap / work its way loose. There are slim plastic clips at the end that stop the pin sliding out, but once these start to break off the constant motion makes the pin slide out very easily. When the pin is loose the clutch-pedal wont depress properly, which means the car cannot be put into gear or even press the clutch-switch to start the engine.

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"GET YOU HOME" QUICK FIX:

1. Remove the trim-panel above the driver's footwell by undoing the T-20 Torx screws holding it in place. If you do not have tools to do this the trim can be forced off firmly and gently without breaking the plastic. The screw heads should pop out of the oblong holes in the panel, which can be bent back into place later and refitted.

2. Locate the end of the clutch pedal-pin where it has come out of the pedal-box, just to the right of the metal bar that attaches to the top end of the clutch-pedal.

3. Manoeuvre the clutch pedal back into position by hand, so the metal bar at the top of the clutch-pedal is straight with the eyelet either side of it in the pedal box and slide the pedal-pin to the left until it is fully into the far eyelet.

** This will get the car moving again to drive home, but the pedal-pin will soon slide back out. Reaching under the trim and locating the end of the pedal-pin will mean you can make sure it stays fully in place while stopped at traffic lights, so you technically run the car like this indefinitely. Still this is by no means a long-term solution. **

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REPLACEMENT:

** You will need 'Clutch Pedal Pin' BMW Part no. 35306761029. **

1. Remove the trim panel above the driver's footwell that surrounds the pedals using a T-20 Torx socket.

2. Remove the coin-tray / stow-box to the right of the steering-wheel by undoing the two screws in the upper corners with a T-20 Torx socket and lifting it out top edge first.

3. Remove the single screw holding the electronics module to the right of the pedal-box using a T-25 Torx socket, remove the module from its housing and rest it somewhere out of the way.

4. Slide the pedal-pin to the right until it is out of the pedal-box.

5. Remove the push-circlip from the lower side of the clutch return-spring using a small flathead screwdriver [the one at the end of the stud that attaches the spring to the pedal itself], slide off the plastic spring-mount and fully remove both springs. [**DO NOT attempt to replace the plastic pedal-pin with the spring still in place as it will likely damage the plastic pin!**]

6. Grease the new pedal-pin.

7. Manoeuvre the clutch pedal back into position by hand, so the metal bar at the top of the clutch-pedal is straight with the eyelet either side of it in the pedal box and slide the new pedal-pin in from right to left until it is fully clipped into the far eyelet.

8. Hold the spring assembly in position against the upper spring-mount and compress it by hand until the lower mount can be pushed back over the stud on the pedal. Replace the circlip.

9. Reverse steps 1-3.

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'DIY' PERMANENT FIX:
If you can't get hold of a new pedal-pin, or if the new one snaps too [which is likely to happen in the end as the pedal-box wears], then a long-term solution can be fettled with a long bolt.

CAUTION: The original pedal-pin is plastic and therefore designed to snap before the pedal-box does. Strengthening it with a metal bolt MAY cause further damage to the pedal-box over time, particularly if the eyelets are worn or the clutch-wear problem is not addressed.

1. Remove the plastic pedal-pin, as above.

2. Find a long M8 or M10 bolt and nyloc-nut. The bolt will need to be about 6 inches long. Any longer and it will foul things under the steering-column, but it needs to be long enough to reach through both sides of the pedal-box and get the nut on at least half a turn into the nylon. A 'shank' bolt [smooth down the shaft and only threaded at the end] is the best type to use. A flat washer on either side is also recommended, thin nylon washers being even better.

3. Take the plastic pedal-pin and drill the hole down the centre out: 8mm for M8 bolt, 10mm for M10.

4. Grease and re-insert the plastic pedal-pin to the pedal-box.

5. Grease the bolt and slide it in from the left side of the pedal-box, so the bolt is entering the far end of the pedal-pin, until the threaded end exits the right side of the pedal-pin.

6. Fit the nyloc-nut, ensuring the thread is into the nylon by at least a half-turn, as the constant pedal motion will work it loose otherwise. DO NOT over-tighten or put stress on the pedal-box!

Thread I started about this on Bimmer-Forums - http://www.bimmerforums.co.uk/forum/f15/2012-f10-530d-clutch-pedal-pin-snapped-twice-t494842/

F10: Centre-console / Arm-rest / iDrive-panel Replacement

The centre ash-tray had been replaced with an aluminium plate for the Police-light switches and stuff, so that needed replacing. The centre-console itself, apart from being black vinyl, which would never do, had holes drilled both sides to mount the Police radio / scanner. There was also blobs of glue all down one side, so after a brief attempt at titivating the damage, I decided a whole new one would be necessary and gave a welcome change up to a leather arm-rest!