Hi



Before I start, I know everyone is going to say Don’t fix it it’s a pain in the ***. But its not about the stop start its about finding out what’s wrong.

Bought the cars 3 months ago 2015 2.2 D

Have a few issues which I'm currently working through. One of the being the Stop start not working. Garage i bought it from fobbed me off until I complained yet again, They did a test and tolde me the errors where duw to the EGR and a fuel sensor which they replaced. God know what the EGR has to do with stop start. Then they promptly went in to liquidation....

It is what it is but I ended up speaking to the Finance company who I bought the car with and they agreed to help me out. Had a diagnostic done and was told that both batteries where in a poor state (Both original batteries and at least 8 years old. Anyways the batteries were changed and the issue still isn’t fixed. I bought the Autel obd and did a diagnostic which showed that there is a fault with the Gateway Module saying a relay is stuck open and the circuit for battery two has failed.

DTC Code B13C5-92



My suspicion is that the module is faulty in some way.

So my intention is to replace the GWM to see if this fixes the issue. In preparation for this I’ve bought a mongoose OBD and have a copy of SDD software running on a laptop. Tested that today and it connects fine and gives me the same error.



My question is am I correct in thinking the GWM is faulty or is there actually a relay in that Battery circuit and if so where. All so I take it changing the GWM is easy enough Ive checked the SDD and seems simple enough to install a new module.

 

SDD should guide you and give suggestions? Did you follow the diagnosis? Does SDD say replace the module?

As you drill down SDD will give a list of possible solutions. The more details you give SDD the smaller number of results. Usually you get a list with % of how likely each outcome is.
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As with any software its a learning process, think i need to look at it a little deeper

 

I hear you on that! SDD is very confusing software to me and I read every thread I can to pick up more details.
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So been playing with the SDD today trying to get to the bottom of this and its come back with

The dual battery system test has failed - Relay 2 - Stuck open


Where is the Relay Ive checked the Fusebox in the boot and there are no relays fitted (should there be)?

More:

Possible causes:

Dual battery control module - Wiring harness fault - Circuits CONTACTOR_2_CTRL and GND - Short circuit to power, ground, open circuit, high resistance

Dual battery fuse box control module - Wiring harness fault - Circuits BATT_2 and GATEWAY and GND - Short circuit to power, ground, open circuit, high resistance

Dual battery control module

Dual battery junction box

Action

Refer to the electrical circuit diagrams and check the contactor 2 control circuit between the dual battery control module and the dual battery fuse box - Circuits CONTACTOR_2_CTRL and GND - Check connections are secure and wiring integrity

Refer to the electrical circuit diagrams and check the dual battery fuse box circuits - Circuits BATT_2 and GATEWAY and GND - Check connections are secure and wiring integrity

If no wiring/connector faults are found, check and install a new dual battery control module

If fault persists, check and install a new dual battery fuse box and run dual battery system diagnostic service routine



Ive Checked over the wiring and all is well as far as I can see.

 

There are no relays in the GWM ( gateway module ). The relays are in the DBJB ( dual battery junction box ), which is under the small battery (i.e. it's not just a plastic support the small battery is on, but the DBJB ) - they often get wet when, when the vents below the rear lights leak, so there could well be some corrosion at that end.
You can probably replace just the replay(s) if need be. ( I don't know what relays they are, so posting photos/ relay part numbers would be nice if you have it dismantled, so others know what to expect in there. )

Relays are controlled by the GWM module however, so it could still be a faulty GWM if the output driver that controls the relay has failed for example.

( stating the obvious here to most people, but just in case someone reads this that doesn't know, don't forget to disconnect both batteries before removing that DBJB. )

 

Thanks for the info Ill get the spanners out today and have a look

 

Great explanation sportbrake_phil!
I did not know what was under that 2nd small battery.
As always you get very cryptic directions from SDD. It would be nice if the software would have told you where these relays are at?
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@Andyd358 Did you manage to find the relays ok?

 

Not yet couldnt get the Module out. Had the car in the garage to sort out a wheel bearing. Gonna have another shot at it over the weekend. I did get the battery out and see the two compartmenst on top of the module with fuzes in them but could not see any relays as such. Ive got another GWM module so was going to swap that over as well.