Ford Ranger IV 2020 - No OBD connection

[rokas]

Hey,

I’ve got a 2020 Ford Ranger and I’m troubleshooting a CAN/OBD issue.
At the OBD port, pins 6 and 14 show close to 0 V, and I measure about 120 Ω resistance between them.
I started digging by disconnecting the SDLC module and checking continuity with a multimeter. I found continuity between SDLC pins 4 & 5 and OBD pins 6 & 14.

However, what confuses me is this: on my truck, the SDLC connector does not seem to have wires in positions 2–5 at all — only pins 6 & 7 on the first row are populated. Mine is a left-hand-drive Ranger.

If there are physically no wires in the SDLC positions that should correspond to OBD pins 6 and 14, how can OBD pins 6 and 14 still have continuity / a CAN connection? Is there a different routing on LHD Rangers, or am I misunderstanding the wiring diagram?

SDLC wiring diagram attached.

One more thing to add. I bought this truck after accident. Truck does not start and I have no history of it.

Any help would be much appreciated!

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[RangerBill]

Hey,

I’ve got a 2020 Ford Ranger and I’m troubleshooting a CAN/OBD issue.
At the OBD port, pins 6 and 14 show close to 0 V, and I measure about 120 Ω resistance between them.
I started digging by disconnecting the SDLC module and checking continuity with a multimeter. I found continuity between SDLC pins 4 & 5 and OBD pins 6 & 14.

However, what confuses me is this: on my truck, the SDLC connector does not seem to have wires in positions 2–5 at all — only pins 6 & 7 on the first row are populated. Mine is a left-hand-drive Ranger.

If there are physically no wires in the SDLC positions that should correspond to OBD pins 6 and 14, how can OBD pins 6 and 14 still have continuity / a CAN connection? Is there a different routing on LHD Rangers, or am I misunderstanding the wiring diagram?

SDLC wiring diagram attached.

One more thing to add. I bought this truck after accident. Truck does not start and I have no history of it.

Any help would be much appreciated!

Do you have battery voltage between ground and pin 13 of the SDLC? Is there battery voltage between ground and pin 24 of the SDLC? Make sure that pins 1 and 14 of the SDLC are grounded.

I wouldn't know what the resistance to ground on the HS Can 4 link would be. Your reading might be normal. Aren't pins 2-5 your OBDII port?

 

[airline tech]

A little more detail:
Any codes being picked up? (com)
Or
Issues with scan tool not communicating?

Has the truck ever ran after accident and where is the damage?

 

[rokas]

There is no obd connection.

There are no wires going to pins 2-5 (mine is left hand drive, which makes sense).
All CAN pairs going to SDLC have 60 omh resistance with SDLC connected.
Grounds are OK. There is constant power to pins 13 and 24 as shown in the wiring diagram.
From wiring perspective everything looks fine.

I expected that SDLC pins 6&7 will be wired to OBD 6&14, but they are not. SDLC pins 4&5 are wired to OBD pins 6&14. However there are no wires going to pins 4&5 to SDLC since mine is left hand drive.

I do not understand how this OBD connection can work at all? Are SDLC pins 6&7 internally rewired to OBD pins 6&14 somehow when some conditions are met?

Module: https://www.ford.com/product/smart-data-link-module-p4000142881?categoryID=9

 

[rokas]

A little more detail:
Any codes being picked up? (com)
Or
Issues with scan tool not communicating?

Has the truck ever ran after accident and where is the damage?

The damage is to the left front. Electronics seem to work, however I cannot get OBD connected to the truck.

 

[rokas]

This is the connector going to SDLC. There are no wires going to pins 2-5.

 

[airline tech]

You need to understand that the Gateway Module has 2 connectors - The Rear Connector is for the Gateway Module (GWM) and the front connector is only for the OBD (DLC) the DLC is not wired direct to the rear connector - The Scan Tool (Communicates) to the GWM for the other networks.

Here is a better diagram

First:
This has had Left Front (Damage) so the battery , BJB (Fuse Box) as well as the (High Current Fuse Box) under the BJB may be compromised.
I know the truck wont start.
But do you get power from the PCM (Power Relay) or the BCM or IPC, meaning does the IPC, Interior Lights, Door Locks etc power up - Does it crank and does the PCM Power Relay (Click)

It appears you are only checking the (Rear Connector) - so far it sounds good and you stated voltage check of can bus (near zero) be more specific (What is the Voltage?)

For a No Communication with scan tool - I would start with the following checks at the 16-Pin DLC.

1. Check for power Pin 16 to Pin 4 - & Pin 16 to Pin 5
2. Check HS1 (Voltage) Pin 6 to pin 4 & Pin 14 to pin 4 or 5 - should be around 2.5 volts
3. Check HS2 (Voltage) Pin 3 to pin 4 & Pin 11 to pin 4 or 5- should be around 2.5 volts

Disconnect Battery:
Resistance Check:
1. HS1 - Pin 6 to Pin 14 - Should be 60 Ohms
2. HS2 - Pin 3 to Pin 11 - Should be 60 Ohms

I am thinking the GWM is dead or the Can Network is dead - yes you verified 60 Ohms at the rear connector - but is it waking? - this is what the can bus voltage checks will tell us

Now we need to check the Internal GWM (Term Resistor) and the front DLC (16 Pin) for any damaged or spread contacts.
1. Inspect the contacts (all wired contacts as noted in diagram above)
2. Disconnect the GWM (Connector) and at the module side (Not the connector)

A. Meter between pins 17 & 18 (HS2) & pins 19 & 20 (HS1)
Spec is 108 - 132 Ohms - This is 120 Ohms (with +/- 12 Ohms Tolerance)

I have a hunch you have a power loss that is not letting the Can Bus to wake so mainly the power feed to the BCM - note this is under the BJB (High Current Box)

The above should give you some guidance on what is going on - hope it helps. Keep in mind that this is for the US Version Ranger - but it should be the same

 

[rokas]

I didn't expect such detailed answer. Thank you very much!

The wiring diagram you posted shows that all OBD pins are internally wired to GWM and those pins accordingly have wires.

I have the module disconnected and checked the pins wiring from OBD to GWM (continuity).

OBD -> GWM
3 -> 3 (there is no wire going to this pin)
4 -> 1 (matches your diagram)
5 -> 14 (matches your diagram)
6 -> 5 (there is no wire going to this pin)
11 -> 2 (there is no wire going to this pin)
14 -> 4 (there is no wire going to this pin)
16 -> 13 (matches your diagram)

I cannot explain this. The wiring seems to be the same as on US version. However internal GWM module wiring seems to be different. Could it be that this module has different versions for different markets?

 

[rokas]

I should also mention that the ignition can be turned on, lock/unlock works.

 

[airline tech]

So yes - this is the internal diagram of the GWM

Internal Pin Outs:

DLC Pin 3 - is fed from C2431 Pin 18
DLC Pin 4 - is fed from C2413 Pin 1
DLC Pin 5 - is fed from C2431 Pin 14
DLC Pin 6 - is fed from C2431 Pin 20
DLC Pin 11 - is fed from C2431 Pin 17
DLC Pin 14 - is fed from C2431 Pin 19
DLC Pin 16 - is fed from C2413 Pin 13

Note: When I was stating - check for power etc , I am talking about from the Front DLC and then the internal (Resistor) is with C2431 disconnected and measuring (Module Side) where the C2431 connector connects to the GWM (we are checking the internal resistor) which is pins 17 & 18 and Pins 19 & 20

 

[rokas]

Checking from OBD side pins 6&14 have infinite resistance to pins 17, 18, 19 & 20 from GTW side.

 

[rokas]

If the module's internal wiring would be the same as you posted in your diagram there would be no problem. Could it be that this module is for RHD drive?

 

[rokas]

One more thing. I have disassembled this module and plugged it in directly.
Grounds (2 wires) OK,
Power (2 wires) OK,
All 5 CAN lines have 60 omh resistance and voltage around 2.5V.

However I have no idea how OBD could work with such GTW internal wiring.

 

[airline tech]

Since it appears that the C2431 matches (US Version) but the DLC side may be different, in other words - what can the scan tool see (Direct) vs GWM (In between)

Internal Pin Outs:

DLC Pin 3 - is fed from C2431 Pin 18
DLC Pin 4 - is fed from C2413 Pin 1
DLC Pin 5 - is fed from C2431 Pin 14
DLC Pin 6 - is fed from C2431 Pin 20
DLC Pin 11 - is fed from C2431 Pin 17
DLC Pin 14 - is fed from C2431 Pin 19
DLC Pin 16 - is fed from C2413 Pin 13

If you go down the 16-Pin side to C2431 Side
using the above as a guide but use all pins 1-16 and find the matching (get a reading) on C2431 side of the connector - we can see which Can Busses are a direct read for the scan tool.

I am more concerned with - Power and Ground - To get scan tool power, also what year is the truck and scan tool you are using - if power and ground are good, you may be able to use OBD connection vs VIN Specific -How far can you get with the scan tool, before it says unable to communicate - it may be the scan tool or scan tool adapter (if using Forscan) it must be OBD Link EX -the cheaper adaptors can be problematic (THIS ISSUE) such as V-Linker

 

[rokas]

I went through all the wires from OBD side. It clearly matches RHD logic, but the wiring is as it is supposed to be for LHD.

3 -> 3 (there is no wire going to this pin)
4 -> 1 (matches your diagram)
5 -> 14 (matches your diagram)
6 -> 5 (there is no wire going to this pin)
11 -> 2 (there is no wire going to this pin)
14 -> 4 (there is no wire going to this pin)
16 -> 13 (matches your diagram)

There is no power on OBD pins 6 & 14 (which makes sense having in mind the wiring). However the OBD device powers up which makes sense too since ground and power wires are OK.

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