P38A SRS + Airbag Fault + Nanocom unable to communicate with ECU

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Soir

Soir

Member
Posts
12
Location
British Columbia, Canada
Hello all, this is my current problem with my 2001 4.6 HSE Range Rover:

I have the red SRS light on. I have the Airbag Fault message on the display upon start-up. My Nanocom is communicating with all other systems except under the Airbag SPS2 tab.

I have reconnected and cleaned the yellow SRS tabs located under the kickplates, door jams, under the seats and the large front sensors under the bonnet. I have yet to address the couple within the dash.

What is of most concern is the Nanocom inability to communicate with the ECU on the Airbag issue. If I can correct the communication issue I am hopeful it will help diagnose/pinpoint all other Airbag problems.

Does anyone have some suggestions?
 
Soir said:
Hello all, this is my current problem with my 2001 4.6 HSE Range Rover:

I have the red SRS light on. I have the Airbag Fault message on the display upon start-up. My Nanocom is communicating with all other systems except under the Airbag SPS2 tab.

I have reconnected and cleaned the yellow SRS tabs located under the kickplates, door jams, under the seats and the large front sensors under the bonnet. I have yet to address the couple within the dash.

What is of most concern is the Nanocom inability to communicate with the ECU on the Airbag issue. If I can correct the communication issue I am hopeful it will help diagnose/pinpoint all other Airbag problems.

Does anyone have some suggestions?
Click to expand...
Check the OBD connector for corrosion, the wires sometimes even corrode off completely. Other than that, it could be a duff ECU.
I assume the car battery voltage is OK?
 
I will need to check the wiring from the OBD to the ECU. Pin 9 to pin 14 for the diagnostic connection as I understand. This will be my first attempt as doing a continuity test so any advice would be appreciated. In addition, any tips for uncovering the location of the SRS airbag ECU?
 
Soir said:
I will need to check the wiring from the OBD to the ECU. Pin 9 to pin 14 for the diagnostic connection as I understand. This will be my first attempt as doing a continuity test so any advice would be appreciated. In addition, any tips for uncovering the location of the SRS airbag ECU?
Click to expand...
The SRS ECU is in the center console behind the cubby box and not easy to access.
Do you have the workshop manual RAVE?
 
Datatek said:
The SRS ECU is in the center console behind the cubby box and not easy to access.
Do you have the workshop manual RAVE?
Click to expand...

I do have the shop manual printed out. Lucky for me the previous owner was an enthusiast who provided me with the thing. Excuse my ignorance but, what does the RAVE stand for?
 
Soir said:
I do have the shop manual printed out. Lucky for me the previous owner was an enthusiast who provided me with the thing. Excuse my ignorance but, what does the RAVE stand for?
Click to expand...
No idea what RAVE actually stands for in relation to JLR products, my kids tell me it stands for an illegal music event.
RAVE is the definitive workshop manual covering various models including P38, Defender, early L322 and possibly others. There are different edditions.
 
I was going to do a continuity test from the OBD port to the SRS ECU, this was suggested by the Nanocom forum. However I reviewed the shop manual and it expressly warns against using a multimeter to check/test SRS components. Not sure what else I can do?
 
Soir said:
I was going to do a continuity test from the OBD port to the SRS ECU, this was suggested by the Nanocom forum. However I reviewed the shop manual and it expressly warns against using a multimeter to check/test SRS components. Not sure what else I can do?
Click to expand...
You can unplug the ecu before testing the communication wire. Pull the battery first. You can test the earth and live to the ecu. :)
 
Soir said:
I was going to do a continuity test from the OBD port to the SRS ECU, this was suggested by the Nanocom forum. However I reviewed the shop manual and it expressly warns against using a multimeter to check/test SRS components. Not sure what else I can do?
Click to expand...

That's because they don't want you to trigger it. Battery off for 20 minutes before you start and then you should be able to test resistance with a digital volt meter as they don't use much current. Always beware any cables in yellow ducting.
 
Grrrrrr said:
That's because they don't want you to trigger it. Battery off for 20 minutes before you start and then you should be able to test resistance with a digital volt meter as they don't use much current. Always beware any cables in yellow ducting.
Click to expand...
Never use a multimeter on any of the lines connected to an airbag or you risk it firing. No problem as Mark said testing continuity from the OBD port to the ECU connector with the connector un plugged
 
Datatek said:
Never use a multimeter on any of the lines connected to an airbag or you risk it firing. No problem as Mark said testing continuity from the OBD port to the ECU connector with the connector un plugged
Click to expand...
I figure it is a bad or loose connection between the OBD plug and the ECU. I am tempted to replace the OBD plug if I can find a new one. Does anyone have a source for one?
 
Soir said:
I figure it is a bad or loose connection between the OBD plug and the ECU. I am tempted to replace the OBD plug if I can find a new one. Does anyone have a source for one?
Click to expand...
I buy OBD sockets on Ebay, I think the plugs are also available, otherwise get one from a breaker.
 
I wanted to provide an update on this to you all. I started to remove the center console to gain access to the SRS ECU and start to perform a continuity check. I removed an aftermarket phone charger the previous owner installed. I also jostled about the center console and my ass hit the steering wheel a few times. So in all that nonsense the SRS and Airbag fault cleared and I was able to now speak to the SRS ECU with my Nanocom. The Nanocom confirmed an intermittent open circuit to the drivers side airbag. I suspect my ass did the repair? The fault has not returned. I am still not sure what I did but there you go for now.
 
Soir said:
I wanted to provide an update on this to you all. I started to remove the center console to gain access to the SRS ECU and start to perform a continuity check. I removed an aftermarket phone charger the previous owner installed. I also jostled about the center console and my ass hit the steering wheel a few times. So in all that nonsense the SRS and Airbag fault cleared and I was able to now speak to the SRS ECU with my Nanocom. The Nanocom confirmed an intermittent open circuit to the drivers side airbag. I suspect my ass did the repair? The fault has not returned. I am still not sure what I did but there you go for now.
Click to expand...
if your ass hit the steering wheel and fault has cleared it would point to a loose connection in the steering wheel spider they are easily replaced if need to be
or just remove the steering wheel and check and clean the sensor
 
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