Snap-On MODIS Scan tool

[Rob371]

Attempting to diagnose intermittent three amigos. I also got a used abs modulator assembly yesterday because one of the valve caps is leaking on top of the modulator. I need to be able to bleed the system with a scan tool. The snap on tool won't communicate with abs system. I've got the correct snap on key (S-25) for the vehicle. So I am not sure if I am experiencing a scan tool communication problem, or a communication problem with the vehicle? Has anybody used the snap on modis for abs diagnostics successfully?

 

[jymmiejamz]

I have a Solus and have never had a problem communicating. I've also never used a diagnostic tool to bleed the brakes after replacing any brake system components.

 

[discostew]

He's talking about bleeding out the modulator. Some systems you have to cycle all the solinoids to get air out of them. But I think you can bleed out these wabco units from the bleeders on the unit.

 

[Rob371]

I'm just looking at the recommended procedure for bleeding. Procedure is to perform conventional method of manual bleeding followed by bleeding modulator via scan tool. At least that's what the tutorial on Atlantic British recommends. I've used pressure bleeder with good success on other vehicles.

As far as the snap on scan tool communication, I can view OBD 2 engine parameters and codes using Global OBD2 and the k-20 comm key but the manufacturer specific s-25 key won't communicate with engine, body, abs. I think it's a scan tool problem.

 

[discostew]

You need to find a guy named pt schram. He will know. I think maybe he's on Facebook Land Rover forums.

 

[discostew]

What scanner will program a used instrument cluster in a LR3? I remember guys saying they can do it. I know snap on says they can do that stuff, but those snap on scanners are crazy expensive. Then you have to spend over a grand every couple years to keep its software current.

 

[Rob371]

WARNING: If any components upstream of brake
modulator, including the modulator itself are
replaced, the brake system must be bled using
the procedure on TestBook/T4, to ensure that all
air is expelled from the new component(s).
WARNING: Do not allow brake fluid to come into
contact with eyes or skin.

this is from the manual. anybody got details on this procedure?

 

[discostew]

Also should mention that all disco2 systems don't come to the diagnostic connector in CAN format. I think the Disco2 was the first Rover to even have engine and trans connected to the diagnostic connector using a CAN network.

 

[discostew]

WARNING: If any components upstream of brake
modulator, including the modulator itself are
replaced, the brake system must be bled using
the procedure on TestBook/T4, to ensure that all
air is expelled from the new component(s).
WARNING: Do not allow brake fluid to come into
contact with eyes or skin.

this is from the manual. anybody got details on this procedure?

The t 4 cycles all the valves in the modulator while running the pump. Can't remember if they want pressure on brake pedal or not. It does it 3 times or so. This expels air from circuits in the valve block that would be trapped in the valves until an abs stop. I've gotten soft shitty brake pedals to get better doing it.

 

[Rob371]

I thought I might just try bleeding at the module by cracking lines the way you would bleed a master cylinder that wasn't bench bled properly or went low because of other leaks. Just thinking out loud here so to speak.

The valve cap has been leaking for several months so I just keep a rag stuffed in there and keep adding fluid. When the three amigos aren't lit everything functions normally. I've wondered if the lights aren't a result of pressure imbalance from the leak although the pedal is always firm.

 

[Rob371]

Also should mention that all disco2 systems don't come to the diagnostic connector in CAN format. I think the Disco2 was the first Rover to even have engine and trans connected to the diagnostic connector using a CAN network.

The procedure on atlantic british shows use of the hawkeye scan tool connected to obd2 DLC for bleeding module.

I guess I'll have to talk to snap on rep on tuesday and see what he can find out for me.

 

[discostew]

Search dweb for shuttle valve faults. That's usually the problem. That or wheel speed sensor and wheel bearing problems.

 

[Rob371]

Search dweb for shuttle valve faults. That's usually the problem. That or wheel speed sensor and wheel bearing problems.

Thanks, I know the common faults. These are common among all abs braking systems. First I need to get passed why the 3 thousand dollar scan tool with vehicle specific comm key that was just purchased doesn't communicate. I can live without traction control and abs for a while. Eventually I need to communicate and bleed module also.

The lights and leak are the real nuisance and for now everything is working. I'm just trying to get the all possible answers before I start ripping and tearing. I need the vehicle on the road right now so I don't want to run into a snag and then guess my way through it.

Everyone hear has been helpful. Don't have all the answers yet but the feedback helps even if nothing more than for moral support.

In the world of diagnostics you must occasionally challenge yourself to fight through the tough ones. With that in mind, next time I'm suggest purchasing a rover please just kick me in the nuts.

 

[SGaynor]

I've had my ABS out and apart to repair the shuttle valves. I bled it by just going to a parking lot/street and stomping on the pedal and getting the ABS to engage. In fact, I've done that for a Chevy ABS pump/assembly as well (2001 Suburban).

No real need for the computer...regardless of what the manual says (It also says there are some "special" tools that are required for certain tasks - other tools work just fine).

As for why the computer isn't talking to it? no clue...

 

[Rob371]

I've had my ABS out and apart to repair the shuttle valves. I bled it by just going to a parking lot/street and stomping on the pedal and getting the ABS to engage. In fact, I've done that for a Chevy ABS pump/assembly as well (2001 Suburban).

I had considered that method as well. I was thinking more in the lines of loose gravel or wait for snow but your approach sounds legit. I got with snap-on today. Turns out there is also special adapter required to communicate with the rover. He actually had one on the truck for under 60 bucks. Now I can communicate with all the modules. Shuttle valve electrical failure is the fault. I got the used module the other day so now I just need to find a couple hours to dink around with it.

On another note, I was searching through the rave manual pdf version I downloaded from another post here. I don't see any electrical diagrams or power distribution. Maybe it's in there and I just didn't see it. Anybody know about this?

 

[jymmiejamz]

The shuttle valve fault is a cheap and easy fix at least.

 

[discostew]

Look in electrical schematics. Info is spread out over several places, not linked together.

 

[JohnB]

You can just put 12 volts to the modulator if you really think its important enough. I did that to mine years ago but I found just a pressure bleeder worked just as well.

 

[Rob371]

I had the right data key for the rover but the wrong data cable. Snap On key S-25 and cable DL-16. Now I can communicate with all the control units. I'm going to swap in the used modulator I picked up but first I will install a new shuttle valve solenoid that I ordered yesterday.

I just didn't want to get it apart and not be able to get it bled properly, particularly since my kid is driving it daily. Thanks for all the suggestions.