How to diagnose a bad immobilizer key?

[DesertPilot]

Is there a way to tell if an immobilzer key has gone bad? My V85TT has cleverly decided to not switch on -- or worse, switch off unexpectedly -- at random and unpredictable intervals, then work fine a few minutes later, and after puzzling over the wiring diagram, testing everything I could get to easily, and eliminating possibilities like the battery and ignition switch, the most likely problems would seem to be a flaky immobilizer key, flaky immobilizer unit, or flaky ECU. Needless to say, I'd be happiest if the problem was just the key, but can't think of any easy way to test this, and I didn't find anything obvious when I searched the forum.

 

[john zibell]

Is there a way to tell if an immobilzer key has gone bad? My V85TT has cleverly decided to not switch on -- or worse, switch off unexpectedly -- at random and unpredictable intervals, then work fine a few minutes later, and after puzzling over the wiring diagram, testing everything I could get to easily, and eliminating possibilities like the battery and ignition switch, the most likely problems would seem to be a flaky immobilizer key, flaky immobilizer unit, or flaky ECU. Needless to say, I'd be happiest if the problem was just the key, but can't think of any easy way to test this, and I didn't find anything obvious when I searched the forum.

The chip in the key is either recognized or not. Once the bike is started, that system doesn't come into play. You have other issues going on. Get to a dealer that can hook up to the bike to detect fault codes.

 

[DesertPilot]

The chip in the key is either recognized or not. Once the bike is started, that system doesn't come into play. You have other issues going on. Get to a dealer that can hook up to the bike to detect fault codes.

Thanks, John! I was wondering what the system in the vehicle would tdo it the key were to fail, and you've answered my question. I checked the fault codes, and the only one it showed, 'P2119 Generic, Throttle Actuator, Control Throttle Body, Range/Performance'. This doesn't seem consistent with the observed symptom, which was, 'instrument panel goes dark and everything except the headlights shuts down'. I'm guessing that code might have meant 'the ECU got confused by whatever really happened'.

Since 'whatever really happened' could possibly be a bad immobilizer unit or ECU, this is, as you've suggested, beginning to look like a dealer issue. From a dealer who has a long wait list at their service department, One month after the bike is out of warranty. Alas...

Be this as it may, I am tempted to try to get a key without an immobilizer chip cut by some local locksmith to see it this reproduces the, "The panel doesn't switch on when you turn the key," problem, which also happens.

 

[john zibell]

Save your money on that key. If the bike doesn't recognize the key it won't activate. Do you have two recognized keys for that bike?

 

[scott_m]

I am fairly certain that this is not an immobilizer problem. I'm betting that this is a power problem.

You say your battery is ok. How do you know? You need to have it load tested at a local auto parts store where they do it for free. I would bet money, that it fails a load test miserably.

This scenario has played out 100x here that I have been involved with, and every single time, the battery turns out to be the culprit.

A load test IS NOT measuring surface voltage across the terminals. I don't care if it says 13V. You can still have 13V of surface charge, and bad cells which will reveal themselves in a load test.

This would explain the intermittent on and off of the display. Your voltage is just enough, then not enough, then just enough, then not enough...

Best of all, this costs nothing to diagnose properly.

 

[DesertPilot]

I am fairly certain that this is not an immobilizer problem. I'm betting that this is a power problem.

You say your battery is ok. How do you know? You need to have it load tested at a local auto parts store where they do it for free. I would bet money, that it fails a load test miserably.

This scenario has played out 100x here that I have been involved with, and every single time, the battery turns out to be the culprit.

A load test IS NOT measuring surface voltage across the terminals. I don't care if it says 13V. You can still have 13V of surface charge, and bad cells which will reveal themselves in a load test.

This would explain the intermittent on and off of the display. Your voltage is just enough, then not enough, then just enough, then not enough...

Best of all, this costs nothing to diagnose properly.

Will do! Thanks! The only reasons I have to believe the battery is OK are
1) The clock doesn't reset, so it's still getting power.
2) The headlights come on even if the instrument panel stays dark, so power is still getting from the ignition switch to the the lights.
This means the battery remains at least partially alive, but I can see how both these things might still work even if it's flaking out. I'll find a place to get it tested.

NOTE: When the bike dies, the instrument panel, fuel pump, and everything except the headlight and that blinking LED shuts off. This suggest to me that power to the panel or the ECU might be getting interrupted.

QUESTION: My understanding of the wiring diagram is that power to the ECU passes through the ignition switch and then the immobilizer unit, so that a bad connection or failure of the immobilizer unit would interupt power to the ECU. How wrong am I?

 

[GerryAZ]

The symptoms you describe are not from a failed key chip. I ordered an extra key when I bought my V85TT. It came as a blank that needed to be cut and programmed. I picked the key up from the dealer and took it to a nearby ACE Hardware to have it cut to match the original keys and then returned to the dealer for programming.

I had a plain blank cut to make sure their key machine worked correctly before having them cut the expensive one. Inserting and turning the plain key causes everything to light up normally with the dash display asking for the user code. Entering the correct user code then allows the bike to start and run normally.

I agree with Scott—your issue is a power problem. It could be a loose ground or battery connection or somewhere in the wiring harness. Although not common, I have had internal connections between battery cells fail due to vibration and heat in my climate. The open-circuit voltage will be normal (and even specific gravity shows full charge if vent caps can be removed to test), but even low current draw will collapse the voltage.

Edited to add: I will look at the wiring diagram this evening for ideas. A failed immobilizer module or loose connections might act differently than inserting an invalid key.

 

[DesertPilot]

The symptoms you describe are not from a failed key chip. I ordered an extra key when I bought my V85TT. It came as a blank that needed to be cut and programmed. I picked the key up from the dealer and took it to a nearby ACE Hardware to have it cut to match the original keys and then returned to the dealer for programming.

I had a plain blank cut to make sure their key machine worked correctly before having them cut the expensive one. Inserting and turning the plain key causes everything to light up normally with the dash display asking for the user code. Entering the correct user code then allows the bike to start and run normally.

I agree with Scott—your issue is a power problem. It could be a loose ground or battery connection or somewhere in the wiring harness. Although not common, I have had internal connections between battery cells fail due to vibration and heat in my climate. The open-circuit voltage will be normal (and even specific gravity shows full charge if vent caps can be removed to test), but even low current draw will collapse the voltage.

Edited to add: I will look at the wiring diagram this evening for ideas. A failed immobilizer module or loose connections might act differently than inserting an invalid key.

Thanks! I was about to get a plain key blank cut to see what would happen, and you've answered that question. A power problem is looking increasingly likely.

I'm thinking Scott's right about the battery, since both shut-downs happened several minutes into a ride, and the second time the bike came back alive all by itself before I even touched anything. That 'fail after it's been used for a while, then come back to life all by itself' behavior does seem like the sort of thing batteries do. And once I find a nearby shop that tests moto batteries -- most just want to sell you those $50 resistance testers -- it's easy enough to pull the thing and take it there for a look. I can recheck all the fuses and cabling under the seat while I'm at it.

 

[scott_m]

Thanks! I was about to get a plain key blank cut to see what would happen, and you've answered that question. A power problem is looking increasingly likely.

I'm thinking Scott's right about the battery, since both shut-downs happened several minutes into a ride, and the second time the bike came back alive all by itself before I even touched anything. That 'fail after it's been used for a while, then come back to life all by itself' behavior does seem like the sort of thing batteries do. And once I find a nearby shop that tests moto batteries -- most just want to sell you those $50 resistance testers -- it's easy enough to pull the thing and take it there for a look. I can recheck all the fuses and cabling under the seat while I'm at it.

Oreilly auto parts will test it for free with a load tester. So will AutoZone, or AdvanceAuto or PepBoys, etc. Any major chain auto parts store will offer this service for free.

I'm fairly positive about your situation.

 

[DesertPilot]

Oreilly auto parts will test it for free with a load tester. So will AutoZone, or AdvanceAuto or PepBoys, etc. Any major chain auto parts store will offer this service for free.

I'm fairly positive about your situation.

The O'Reilly I always use doesn't do battery tests these days and my favorite Pep Boys closed recently, darn it, but I took the battery by Autozone for a load test. amd it checked out OK. While I was putting it back in, I verified that the main and secondary fuse boxes are getting power, that the fuses and sockets were all OK, and spritzed everything with contact cleaner. I know the ignition switch is OK because the headlight switches on even when the panel stays dead. Immobilizer problems seem off the table, since as Gerry pointed out, that wouldn't explain why the panel wouldn't switch on. It's possible a battery terminal might have not have been tight enough. The gods watch how we tighten them, to punish us if we falter. I tightened them up a bit more carefully this time. I'll take the bike out for a ride this afternoon to see how it does, and toss my multimeter in the topcase so I can see what's still getting power if it decides to shut down again.

The symptom was, "Sometimes the bike shuts down and the panel goes dark, exactly as if the key had been turned off." Now that the battery, ignition switch, and fuse boxes check out OK, the only other causes I can think of offhand would be a bad connector somewhere else, some problem inside the wiring harness, or some intermittent problem with the instrument panel or ECU. One thing I haven't been able to tell from the circuit diagram is, "Could a problem at the ECU end keep the instrument panel from turning on, or could a problem at the instrument panel end disable the ECU?" If someone knows, that would help eliminate some possibilities.

I'm not too worried. This will all get sorted. But I am getting rather curious as to what the problem might be.

 

[Vagrant]

Seeing as you reported it to the dealer and he did a new map they should still honor warranty.

 

[scott_m]

You have a “goodwill claim” if ever there was one.

Being on good terms with your dealer is worth its weight in gold now. They can petition on your behalf for Moto Guzzi to pay for any necessary diagnosis and repair under “goodwill”.

 

[DesertPilot]

Looks like the battery terminals were not the problem. Rode to the cafe for lunch, took a long route back, and 20 miles into the ride... same deal... bike shut down without warming, then switched back on 30 seconds later.

I've checked everything I can see and reach without doing some serous disassembly and couldn't find any problems. These things happen. Unless inspiration strikes, I'll give the dealer a call when the open on Tuesday. They've got one of the better shops in the Bay Area and I've had good luck with them in the past. In the meantime, I'll be forced to ride my wife's Ducati Scrambler. Yes, I know I'm not going to get much sympathy there

Thanks, everyone, for the excellent advice! It was a big help eliminating many of the possibilities!

 

[Vagrant]

The words "this bike is unsafe to ride" is what will get Guzzi's attention.