non starting mystery...

[tooter]

Got a mystery here, and these are the symptoms:

When the key is in the ON position, all the accessories work, except the instruments don't turn on and the led section of the dash remains blank. And when turning to START nothing happens. No cranking. No clicking. Nothing.

Removed and tested all the fuses. They're all good. Everything looks all plugged in like it should be.

Plugged in the OBD computer and turned the key to the ON position. It powers up and tries to communicate with the ECU but says it can't and says make sure key is in the ON position.

I'm stumped... So does anyone here have any suggestions on how to solve this mystery? I'm open to trying anything.

Greg

[fnkngrv]

Have you done any work with the ignition or ECM lately? Have you checked your battery terminal that they are clean and have GREAT contact? I ran into that actually at NEFR and found out that the culprit was the link in the middle of my disconnect assembly.

[tooter]

Originally Posted by fnkngrv

Have you done any work with the ignition or ECM lately? Have you checked your battery terminal that they are clean and have GREAT contact? I ran into that actually at NEFR and found out that the culprit was the link in the middle of my disconnect assembly.

No, I've never done any tuning so all of the wiring is completely intact with no splicing in of any aftermarket components. And the battery terminals are pristine as the car is only a year old. But thanks for the suggestions.

By the way, do you know of any interlinks which prevent turning on the ignition? Everything else works except the ON and START positions of the key switch. The ACC position works normally.

[CTScott]

I think it may be your new manifold!

I would triple check the AM2 fuse in the under-hood fuse panel.

If that is OK. Listen to the relay module below that fuse while someone else turns the key from OFF to ON and see if the IG2 Relay clicks.

[tooter]

Ok, Scott, I will.

[CTScott]

Correction: You have a 3rd gen. Still check the AM2 fuse under the hood, but the IG1 and IG2 relays are now in the junction block assembly under the driver's side of the dash.

[CTScott]

Also, do other things work or not work with the key on (like wipers, headlights, blinkers, radio, etc.)?

[tooter]

The 10amp IG2 fuse is good.
The relay does not click when the key is turned.
The relay coil terminals have continuity.

[tooter]

Originally Posted by CTScott

Also, do other things work or not work with the key on (like wipers, headlights, blinkers, radio, etc.)?

Yes. Everything else works normally.

[tooter]

Originally Posted by CTScott

Correction: You have a 3rd gen. Still check the AM2 fuse under the hood, but the IG1 and IG2 relays are now in the junction block assembly under the driver's side of the dash.

Ok. I'll check those...

One relay under the dash clicks in the ON position, another clicks in the START position.

But no instruments and no starting.

[fnkngrv]

Originally Posted by tooter

No, I've never done any tuning so all of the wiring is completely intact with no splicing in of any aftermarket components. And the battery terminals are pristine as the car is only a year old. But thanks for the suggestions.

By the way, do you know of any interlinks which prevent turning on the ignition? Everything else works except the ON and START positions of the key switch. The ACC position works normally.

The only other that that I personally ran into a similar symptom what when the ground on the driver's side of the block had been lose sorry.

Your symptoms are very intriguing to say the least!

Best of luck...I will be following to hear the outcome.

[tooter]

Ok. I'll check the grounds.
At this point I'm trying everything.

[tooter]

Checked the grounds and they're all intact. Does anyone else have any ideas?

[Mittelklasse]

Can you turn on your A/C blower fan in the ON position?

[CTScott]

Originally Posted by tooter

Checked the grounds and they're all intact. Does anyone else have any ideas?

Check the 60A fusible link on the positive battery terminal.

[tooter]

Originally Posted by Mittelklasse

Can you turn on your A/C blower fan in the ON position?

Yes, it turns on normally.

[tooter]

Originally Posted by CTScott

Check the 60A fusible link on the positive battery terminal.

Took everything apart at the positive terminal and both the main and the alternator fusible links are good. And there is power at both the alternator and the starter.

You know, it is behaving like there is something disabling the ON and START circuits from operating. And although the OBD computer powers up fine, it is not able to communicate with the ECU, so there seems to be no power going to the ECU.

Might you know if there any sort of "fail safe" disable mechanism that may have gotten triggered? I saw in the Owner's Manual there is an anti theft ignition disable security device, although my model supposedly doesn't have it because there is an empty spot where the LED indicator would be at the leading edge of the dash near the passenger side of the windshield.

I'll try any other suggestions you can think of...

[CTScott]

The cluster gets constant power from the ECU-B fuse and switched power from the MET fuse and illumination power from the PANEL1 fuse. It also gets a power feed from the HAZ fuse, as it directly drives the turn signals.

The IG2 Relay feeds the MET fuse power.

If all of those fuses are good, check the voltage on the light blue (ECU-B) and pink (MET) wires, which are right next to each other on one corner of the larger cluster connector. The ECU-B should have power all the time and MET should have it only when the ignition is on.