On my mk2 Focus the airbag and seatbelt lights will not go out.

I have used forscan and have the code U1900-60 in the ic module, also found that forscan doesn't find the rcm module.

Have checked plugs under seats and on rcm module.

Any ideas what else to look at?

TIA.

The U1900 is a canbus error code and in a Mk2 Focus this is invariably caused by the common cracked solder joints in the IC. There are numerous threads on this topic on the forum.

I've had the IC out and looked at the solder joints under a microscope and could not see any cracks.

I don't understand why forscan doesn't pick up the rcm module. 

I was wondering if the U1900 code is because it can't communicate with the rcm module.

U1900 code is often present with failed solder joints in the cluster where the connector pins are fixed to the pcb.

this requires a strip down of the cluster.

if it hasn’t been been reconditioned by now, it’s probably on borrowed time anyway due to degradation of the lead free solder.

had a 2008 ST tested (£35) resoldered  about (£100)

14 hours ago, MarkRS9 said:

I was wondering if the U1900 code is because it can't communicate with the rcm module

Some time back forum member @isettaposted a thread on work he had to do on a Mk2. It involved re-wiring the entire canbus to eliminate faults caused by faulty connectors. I believe the bus routes through at least two connectors under a panel in the passenger footwell. Unfortunately the search facility on the forum is so useless I can't find the thread. Hopefully one of the more knowledgeable members can advise on the actual routing of the bus and which connectors to check.

14 hours ago, MarkRS9 said:

I've had the IC out and looked at the solder joints under a microscope and could not see any cracks

Did you dismantle the IC and look at the joints for the main harness connector? As @RL123says if the cluster hasn't been resoldered it will need doing at some point, and it should be done using new tin/lead solder, not by reflowing the lead-free rubbish.

3 hours ago, mjt said:

Some time back forum member @isettaposted a thread on work he had to do on a Mk2. It involved re-wiring the entire canbus to eliminate faults caused by faulty connectors. I believe the bus routes through at least two connectors under a panel in the passenger footwell. Unfortunately the search facility on the forum is so useless I can't find the thread. Hopefully one of the more knowledgeable members can advise on the actual routing of the bus and which connectors to check.

Did you dismantle the IC and look at the joints for the main harness connector? As @RL123says if the cluster hasn't been resoldered it will need doing at some point, and it should be done using new tin/lead solder, not by reflowing the lead-free rubbish.

I did completely dismantle the IC and look at the joints to the main harness connector, I know I will need to get it resoldered at some point.

I may be wrong, but I wouldn't have thought it would cause the rcm module to be invisible to forscan. 

I would have thought you would have had other codes as well, was that ‘u’ code the only one?

many modules communicate via the hs and ms can buss network hence I would expect some other dtcs .

I also have code B119F:00-2F (GPS) in Speech Recognition Module. 

Just the one ?  Sorry appart from looking at the gem/BCM and it’s plugs, I cannot suggest anything else.

On 6/4/2023 at 8:18 PM, MarkRS9 said:

also found that forscan doesn't find the rcm module.

I came across an old Profile for my old Mk 2.5 Focus and the RCM was on the MS Can Bus along with the ACM and the GEM. 

Presumably these Modules are showing up assuming that your Mk2 is the same, and you have tried to create a new Profile in case there was a glitch when you connected.

The only time I have had a Module not showing up in FORScan was when it was completely dead. In my case there were non-communication codes from the Modules that should have been connecting to the dead one.  

Every time I have done a scan with forscan I have not saved a profile, so should scan for everything. 

All other modules are showing up. 

Hi Mark,

What year is your Focus Mk2 ?

8 hours ago, unofix said:

Hi Mark,

What year is your Focus Mk2 ?

It's 2010 Focus RS.

The RCM may have failed.  It's not common but does happen occasionally. 

For the sake of £20 I'd try plugging in a used one from ebay or breakers yard.  

Already ordered a used RCM from ebay, just waiting for evri to deliver it. 

5 minutes ago, MarkRS9 said:

just waiting for evri to deliver it. 

Should be here in time for Christmas 🤣

Quick update.

Received my second hand RCM a couple of days ago.👍

Only managed to find time today to try it and result is the same, Forscan will still not find the module.

Think I will now get the IC resoldered and see if that helps.

Sorry if you have already answered this before, but what connection lead are you using ?

The missing RCM form FORScan scan is something we see with the eBay/AliExpress type of ELM327 leads.

Can't remember what the lead is called, but it's a new one with auto switching which was recommended on this forum. 

sounds like you have the 'vLinker FS' like the one shown in this Amazon link below, if so that should not be causing any problems 👍

https://www.amazon.co.uk/Vgate-vLinker-Adapter-FORScan-MS-CAN/dp/B0952P4MLP

That's the one. 

Have you checked the fuse for RCM?  

Would be annoying if it was blown after all this testing, though I've just realised it isn't mentioned in this thread at all.

Just to be aware the pins to pcb in the cluster are not the only connections that use the lead free solder in there. People have had issues with other joints, resistors etc. within the cluster.

8 minutes ago, RL123 said:

Just to be aware the pins to pcb in the cluster are not the only connections that use the lead free solder in there. People have had issues with other joints, resistors etc. within the cluster.

I was thinking this earlier with the other thread today (MOT fail one).  The OP over there specifically mentioned soldering the plug, not clear on whether they also checked the rest of the board. 🤔

5 hours ago, TomsFocus said:

Have you checked the fuse for RCM?  

Would be annoying if it was blown after all this testing, though I've just realised it isn't mentioned in this thread at all.

I have had every fuse I can find out and tested and are all OK.