VW T4 Forum - VW T5 Forum banner
1 - 20 of 28 Posts

·
Registered
2007 T5 wiith a 5.1 Facelift
Joined
·
20 Posts
Discussion Starter · #1 ·
Occasionally, my van will not crank, all the ignition lights come on but it will not crank, there is no starter solenoid click.
After leaving it for an hour or so, it will start and run normally, but with an engine fault light. While the light is on, the gear indicator on the dash lights up and shows that all gears are selected, however it runs and changes gear fine.
After a couple of days running , the engine fault light will go out and the gear indicator light will work correctly and all seems fine - happy days - or so I thought.
The above cycle has occurred a few times now.
I took it to my local local garage and they diagnosed a G28 fault (which makes sense for the engine not cranking), but it seems strange that the gear indicator would go into a weird 'all gears selected' mode.

Any thoughts anyone?
 

·
Special Rapporteur
Joined
·
10,535 Posts
Agreed - a G28 fault should not lead to the engine not cranking, though it might crank but not start. As B&T says, it's almost certain to be the inhibitor switch.

The "all gears selected" display mode varies (I think) depending on what type of instrument panel you have, and is more typically an inverted display, where the background colour is white and the symbols dark (if that's possible on your spec of display). All it means is that the gearbox has logged an error - in this case probably the fact that the gearbox is in neutral/park but the inhibitor switch says it's not.
 

·
Registered
2007 T5 wiith a 5.1 Facelift
Joined
·
20 Posts
Discussion Starter · #6 ·
I did go up and down the box and it worked once, but only once. On the dozens of other occasions, it did nothing to help. What is the inhibitor switch, where is it and what does it do?

Could a Engine Speed Sensor (G28) loose or Engine Speed Sensor (G28) faulty trigger the inhibitor switch?
 

·
Special Rapporteur
Joined
·
10,535 Posts
The inhibitor switch on an auto prevents you from operating the starter motor when the gearbox is in gear. It is typically within the gear selector assembly. The T5 is a little more complex though, as it includes an interlock mechanism as well.
 

·
Registered
2007 T5 wiith a 5.1 Facelift
Joined
·
20 Posts
Discussion Starter · #8 ·
Thank you Triffic, that was a great and easy to understand answer.
 

·
Registered
Joined
·
1,576 Posts
As said above, the G28 fault won't stop the cranking. There will be fault with the starter system that's preventing cranking, most likely in the auto box inhibitor circuits, seeing as you have weird gear indicator faults.
I imagine the G28 fault is present because the ECU is expecting an output from it, but nothing is happening due to no cranking. Do you know what the exact fault code and associated text is?
 

·
Registered
2004 T5 2.5 174
Joined
·
2,583 Posts
They probably only looked in the engine ECU, if you have all the gear selected lights on at once there should be a code stored in the Transmission Control Module (TCM). Some faults can lead to non-start or limp home mode. But in fact, a complete scan of all the computers on the van is best. Anyone with VCDS can do this for you. :)
 

·
Registered
2007 T5 wiith a 5.1 Facelift
Joined
·
20 Posts
Discussion Starter · #11 ·
It's booked in on Thursday, It did it again today, you are absolutely right, when I turn the key, it's exactly as if it is in gear and it won't crank. I noticed that the gear indictor corresponded to the selected gear for a split second when I turn the key, then all the gears appeared to be selected = no crank. I tried starting in neutral as well - no good. I went up and down the box several times, also no good.
Eventually around 90 mins after I tried to crank for the first time unsuccessfully, it started, but the ECU light was illuminated and it wasn't showing which gear I was in on the dash, all gears (PRNDS) appeared selected and it didn't display which D gear I was in when driving. In a couple of days, the ECU light will clear itself the gear display will work as it should until the no-crank situation occurs again, it happens every two weeks or approx 15-20 successful starts, each time after 60-90 mins, it will crank and start, but not showing which gear is selected.
 

·
Registered
2004 T5 2.5 174
Joined
·
2,583 Posts
When all the lights come up together it's a bit like a transmission version of the engine management light or the glow plug light on some vans. It shows that a fault is present. It probably will have a code in the TCS or one or more other controllers but it is just worth a quick check that the brake light switch is working because some quite small things can cause that problem (as well as some quite big things!)
 

·
Registered
2007 T5 wiith a 5.1 Facelift
Joined
·
20 Posts
Discussion Starter · #14 ·
I have a couple of transmission codes, can anybody help please as to the cause:

01045:008
00258:010

I have an intermittent no crank situation, the only way to clear it is to leave it for 90 mins or so, then it will crank and start and drives fine, however, all gears are illuminated on the dash and I have an ECU light in the dash. Usually after a couple days it will all return to normal for a couple of weeks and the the cycle starts again with a no-crank situation.
I have no hair left.
 

·
Registered
2007 T5 wiith a 5.1 Facelift
Joined
·
20 Posts
Discussion Starter · #16 ·
01045:008 is the Tiptronic switch F189 - Possible Causes
  • Wiring problem
  • Tiptronic switch F189 faulty
  • Tiptronic magnet housing alignment problem

00258:010 is the Solenoid Valve 1 (N88) - Possible Causes
  • Wiring/Connectors from/to Solenoid Valve 1 (N88) Open or Short to Ground
  • Solenoid Valve 1 (N88) faulty
Does anyone know where the F189 switch and the N88 Sol valve are located? How easy are they to access and swap out?

It is a 2007 t5 2.5 BNZ Tiptronic 130bhp I'm not sure of the gearbox number.
 

·
Registered
2004 T5 2.5 174
Joined
·
2,583 Posts
I'm no auto guru but I believe the F189 is in the cab under the gear lever. But if you can get access to VCDS I believe you can check that switch is responding to each position of the gear lever correctly without any dismantling. You need to go into the transmission controller and look at measuring blocks while moving the lever through all the positions. You should the corresponding changes on the screen.

The N88 solenoid will be on (or in) the auto box.
 

·
Registered
2007 T5 wiith a 5.1 Facelift
Joined
·
20 Posts
Discussion Starter · #18 ·
Thanks T5, the trouble is that it's intermittent, it's booked in on Friday for diagnostics, but if I can drive it there, then the fault won't be present as the gearbox will be working properly- catch 22 :(.
I'm thinking sod it - just swap out both items. When you say N88 is in the box, does this mean dismantling the box?
 

·
Registered
Joined
·
2,045 Posts
Thanks T5, the trouble is that it's intermittent, it's booked in on Friday for diagnostics, but if I can drive it there, then the fault won't be present as the gearbox will be working properly- catch 22 :(.
I'm thinking sod it - just swap out both items. When you say N88 is in the box, does this mean dismantling the box?
I believe all of the solenoids are in the gearbox valve body. This is accessed by removing the sump plate and can be unbolted & disconnected for repair or replacement with the gearbox in-situ. It should be a VW exchange part.
 
1 - 20 of 28 Posts
Top