T4 Won't Communicate

sumpy 130 · 2nd June 2010, 19:44

Whilst having a service, I asked the garage to sort out my SRS light being on all the time (having already done all the normal under seat wiring etc.). Having spent all day trying to find out what's wrong, the garage can't get their T4 to communicate at all with the car. They suggest that as the car is working all right (apart from the SRS light) that I leave well alone, as it is going to start costing a lot for further in depth investigation. Any suggestions?

By the way the garage is a well respected ex-main dealer that I have used for years and trust completely.

Departed · 2nd June 2010, 19:50

There's a whole stack of possibilities, starting with the fuse that supplies power to the diagnostics socket, the k line having come out of the socket, a short on the k line. It's also possibly a problem with their tester.

pab · 2nd June 2010, 19:52

regarding the airbag light,remove the appropriate fuse from the passenger footwell fuse box and leave for 20 minutes so the air bag module discharges.

someone with T4 knowledge will help you with the other problem

sumpy 130 · 2nd June 2010, 20:24

Many thanks for the quick replies. I'll try the suggestions out at the weekend. With regards to the SRS fuse, does the light remain on with a holding circuit hence the need to remove the fuse to clear it following fixing of any faults? Or is it just a safety precaution prior to working on the system?

BigRuss · 2nd June 2010, 20:26

The SRS light will go out when the cause is identified and remedied.

Chances are T4 will communicate with the car it just wont communicate with the SRS module unless as stated by lowedb there's a wiring problem or fuse blown.

I had this the other day on a members car if you use the vehicle diagnostics function then it will fail when it tries to communicate with the SRS ECU.
However the other ecu's can be interrogated by using the system diagnostic functions on T4 it just takes a little longer to do it that way.

Please before doing any investigative work on the SRS system yourself take the necessary precautions, disconnect battery as above first and do not apply any voltages to the wiring to test for continuity without disconnecting SRS module and all the airbags and pretensioners

Russ

Lovel · 2nd June 2010, 21:12

The first time I have seen failure to communicate with T4 is due to water ingress in the satnav plugs in the r/h/rear wheel arch of the car. It was pulling the K-bus voltage down by shorting, also resulted in some other strange phenomena on the car though which the op would have reported by now so probably not?

The second time was tonight, although off thread a little the T4 says incorrect diagnostics selected for a x reg Rover 25 1.8 with CVT box. Does anyone know which disc I should use?

JohnDotCom · 2nd June 2010, 21:48

Keith had a problem on mine caused by Custom remap and Synergy box,
it took several attempts etc,
but Russ didn't seem to have the same problem recently or others,
and I had turned off Synergy box.
Not sure if relevant in this case but may be.

BigRuss · 2nd June 2010, 22:01

Quote:

Originally Posted by Lovel

The first time I have seen failure to communicate with T4 is due to water ingress in the satnav plugs in the r/h/rear wheel arch of the car. It was pulling the K-bus voltage down by shorting, also resulted in some other strange phenomena on the car though which the op would have reported by now so probably not?

The second time was tonight, although off thread a little the T4 says incorrect diagnostics selected for a x reg Rover 25 1.8 with CVT box. Does anyone know which disc I should use?

I would have thought DST0005V would have covered it, although I must admit I haven't tried it on that model

Russ

Lovel · 3rd June 2010, 21:30

Quote:

Originally Posted by BigRuss

I would have thought DST0005V would have covered it, although I must admit I haven't tried it on that model

Russ

Apologies for being unrelated to thread, FYI, I finally got it to work with DJR0013V.

BigRuss · 3rd June 2010, 22:16

Quote:

Originally Posted by Lovel

Apologies for being unrelated to thread, FYI, I finally got it to work with DJR0013V.

Not a disc I have I'm afraid, is it one of the model specific ones?

Russ

2nd June 2010, 19:44	#1
sumpy 130 Regular poster Rover 75 Diesel Join Date: Mar 2010 Location: Bristol Posts: 35 Thanks: 0 Thanked 1 Time in 1 Post	T4 Won't Communicate Whilst having a service, I asked the garage to sort out my SRS light being on all the time (having already done all the normal under seat wiring etc.). Having spent all day trying to find out what's wrong, the garage can't get their T4 to communicate at all with the car. They suggest that as the car is working all right (apart from the SRS light) that I leave well alone, as it is going to start costing a lot for further in depth investigation. Any suggestions? By the way the garage is a well respected ex-main dealer that I have used for years and trust completely. Last edited by sumpy 130; 2nd June 2010 at 19:45.. Reason: spelling!

2nd June 2010, 20:26	#5
BigRuss Premium Trader 75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4) Join Date: Jul 2007 Location: Liversedge, West Yorkshire Posts: 5,405 Thanks: 1,105 Thanked 1,340 Times in 661 Posts	The SRS light will go out when the cause is identified and remedied. Chances are T4 will communicate with the car it just wont communicate with the SRS module unless as stated by lowedb there's a wiring problem or fuse blown. I had this the other day on a members car if you use the vehicle diagnostics function then it will fail when it tries to communicate with the SRS ECU. However the other ecu's can be interrogated by using the system diagnostic functions on T4 it just takes a little longer to do it that way. Please before doing any investigative work on the SRS system yourself take the necessary precautions, disconnect battery as above first and do not apply any voltages to the wiring to test for continuity without disconnecting SRS module and all the airbags and pretensioners Russ __________________ Replacement Key Service http://https://the75andztclub.co.uk/...d.php?t=244732 Full T4 Testbook diagnostics available. Diesel ECU repair and replacement. Options enabled or disabled as required. Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160 MG 160 V6 to 177 upgrades available P.M. for details.

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2nd June 2010, 19:50	#2
Departed Retired -- Join Date: Jan 2007 Location: -- Posts: 3,785 Thanks: 0 Thanked 4 Times in 4 Posts	There's a whole stack of possibilities, starting with the fuse that supplies power to the diagnostics socket, the k line having come out of the socket, a short on the k line. It's also possibly a problem with their tester.

2nd June 2010, 19:52	#3
pab Banned MG ZT V6 190+ Join Date: Sep 2008 Location: Leeds Posts: 33,223 Thanks: 41 Thanked 1,614 Times in 1,416 Posts	regarding the airbag light,remove the appropriate fuse from the passenger footwell fuse box and leave for 20 minutes so the air bag module discharges. someone with T4 knowledge will help you with the other problem

2nd June 2010, 20:24	#4
sumpy 130 Regular poster Rover 75 Diesel Join Date: Mar 2010 Location: Bristol Posts: 35 Thanks: 0 Thanked 1 Time in 1 Post	Many thanks for the quick replies. I'll try the suggestions out at the weekend. With regards to the SRS fuse, does the light remain on with a holding circuit hence the need to remove the fuse to clear it following fixing of any faults? Or is it just a safety precaution prior to working on the system?

2nd June 2010, 21:12	#6
Lovel I really should get out more....... P6B, L550, Imp, F56, Commando Join Date: Nov 2006 Location: Aberdeenshire Posts: 2,886 Thanks: 352 Thanked 677 Times in 440 Posts	The first time I have seen failure to communicate with T4 is due to water ingress in the satnav plugs in the r/h/rear wheel arch of the car. It was pulling the K-bus voltage down by shorting, also resulted in some other strange phenomena on the car though which the op would have reported by now so probably not? The second time was tonight, although off thread a little the T4 says incorrect diagnostics selected for a x reg Rover 25 1.8 with CVT box. Does anyone know which disc I should use?

2nd June 2010, 21:48	#7
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	Keith had a problem on mine caused by Custom remap and Synergy box, it took several attempts etc, but Russ didn't seem to have the same problem recently or others, and I had turned off Synergy box. Not sure if relevant in this case but may be.