Thread: Checking OBD2 port (D3) - have I broken it..?

The OBD2 reader (Ancel for JLR) worked fine from purchase last month - used it about 5 or 6 times, read all codes, erased codes effectively.
I plugged int it (perhaps to roughly and incorrectly, due to beer) and suddenly got multiple errors, flashing hazard, relays (for central locking, no start and blank reader screen on the Ancel.

IMG_4934.jpg

IMG_4932.jpg
Engine System and Xmas lights faults.jpg

I took the negative off the battery and pumped the brake pedal. Got back in the car and it started fine, with none of these errors (D3's lCD screen did give me known ongoing fault 'low coolant level error' - probably a dodgy float - I have a new overflow tank ready for install.

Accessing (removing) the D3 OBD2 port

1. Take the negative off the battery
2. Remove the under the steering wheel trim panel (beige ABS)
3. Remove the trim above the pedals (black ABS) - two 180 degree screws at the front, carpeted side panel has a clip you pull on, but ours had a small screwed added by PO or someone. slide it out enough to unplug the footwell light, then swing the passenger side end around side way and mucsh the driver side end back and then out to clear the RH kick trim.
4. Remove the two screws holding the OBD2 port, using a torx bit (Looks like T20 or T25, can't remember now) and a mirror or the front camera on your phone to see the screws

IMG_5036.jpgIMG_5042.jpgIMG_5041.jpgIMG_5044.jpg
IMG_5145.jpgIMG_5154.jpgIMG_5156.jpg
IMG_5159.jpgIMG_5160.jpgIMG_5162.jpg
Checking/Adjusting receivers on the OBD2 port.

1. Use something as a 'dummy pin' (perhaps a sewing pin or paperclip) to test how tight each of the receivers in the port is. If there is little resistance when pushing/pulling then the receiver might be loose and not allowing a consistent connection.
2. To adjust the tightness of a receiver and to inspect it, you can remove it but using a probe to pull back on the tab/lever on the inside edge of that receiver in the OBD2 port. The tab is about 2mm wide and is sprung (doesn't stay open),, so use a probe to level it away from the receiver and gently pull the river out of the back of the black (there will be very little to no resistance if the tab/lever is pulled back correctly. I found it easiest to hold the port/plug in one hand, using my index finger to put a little tension on the wire, then using my other hand to pull back the tab/lever.
3. Inspect the connection for damage, corrosion, water etc (I found none).
4. If the receiver is loose, adjust it by using a probe-tip (I used my multiple meter probe), pushing it into the inside of the receiver tip and pushing on the flange to close the gap as much as you see fit, As for what is needed for a good connection, I found some receivers were 'open' about 2mm, and some less than one mm. I pushed all of them such that they were a little less that one mm open.

IMG_5203.jpgPulling the tab away to release the receiver (exits it from the back)
IMG_5204.jpgReleased connector (receiver) looks like this

IMG_5210.jpgPushing the connecting surface from behind to make it tighter

The wiring diagram for the OBD2 port is as follows (I do not know if there are variations with the L319 years). NB the purple wire at 12 was not present on this vehicle D3 2009.
IMG_5018.jpg
IMG_5225.jpg My D3 2009 OBD2 port wiring. Note when testing to always insert probe in the back of the plug, to avoid opening out the connectors too much.

Fuse 63 (10Amps) provides 12v constant on the green wire, and checking fuse 63 (behind the glove box) is the first step if you have no power to your OBD2 reader. In this case, the fuse was fine (I swapped it a few times with other 10A fuses, without fixing my problem (OBD2 reader not powering up, multiple faults appear when plugging in).
The OBD2 port is ISO 15765-4/SAE J2480 I believe. Here are pinouts

1. (empty)
2. (empty)
3. YW medium speed high DCL +. CANBUS high (Ford proprietary) (I do not know the required voltage that should be here, nor the ohms expected between 3 and 11
4. B Ground / negative
5. B Ground / negative
6. YN High CANBUS 2.5volts 61-62Ohms between 6 and 14 (battery negative terminal must be off)
7. (empty)
8. GW Transmission control module
9. R ABS module
10. (empty)
11. YU medium speed low DVL - CANBUS low (Ford) “
12. (empty) but given in diagram as P Restraints control module
13. (empty)
14. YN low CANBUS. 1.5volts (see Ohms with 6 above)
15. (empty)
16. LG 12v positive constant source

Testing voltage supply checks (battery connected)

1. Check 12v (positive) supply to 9 (ABS) and 16 (Supply)
2. Check voltage supply to 14 (CANBUS low - should be 1.5v)
3. Check voltage supply to 6 (CANBUS high - should be around 2.5v)
4. What to check on Ford proprietary 3 and 11 I do not know.

Testing resistance and continuity (remove battery negative lead)

1. Check Ohms resistance between CANBUS 6 and 12 (should be around 61 or 62 Ohms)
2. Check continuity and Ohms (should be very low) from the two black Ground/negative wires 4 and 5 to ground/chassis - I used a bolt coming through the firewall
3. Check Ohms resistance of CANBUS wiring to ground (should be around 2.4KOhms - ie very high)