Part locating 99 Fuse box assembly (1 Viewer)

[kevgentile]

Good Luck! So much of this stuff is clear as mud (no pun intended) and it's hard when you don't know what's been done.
I love the hundred so much, just wish it was a little more analog.

I agree, me too. I was looking at a 200 series but that was my first thought, too many things to potentially fail.
I'll be retiring from being a full-time mechanic and looking for another way to make a living, so I'll lose all access to tooling and diagnostics.
Would hate to have to fix anything newer then a 100.

But yes, having to work around someone else's attempts is annoying. I'm new to the platform so I don't know all the little tricks. I know we're on the right track after tracing the voltage loss at the ecm and tracing the wiring diagram back to the junction. Now just need to sort out the keys

 

[kevgentile]

You may have seen this already. This test will not work for you if your key is not working or programmed properly. @Mauser will be able to help you with resetting ECM and program new keys.

I did do a jumper but same no start since the keys are not recognized, I'm assuming since the light is continuously flashes, I'm assuming that's the message.
Also, what doesn't make sense is that the keys are married to the ecm and not the other way around, so my assumption is that the original ecm should recognize the keys.

Diving into it tomorrow. Worst case, I'll reach out to Mauser.

Thanks!

 

[Mauser]

I'll open the block up tomorrow. Since I just bought the truck, for the sake of time and cost I'll probably go the bypass vs a replacement unit.

Unfortunately, after all the parts thrown at it by the last owner, he hired a lock smith and opened up both ecm's. I don't know what he did.
The keys are no longer recognized by either ecm, the key light flashed continuously never steady state.
Saw a obd "reset" tool sent with some replacement ecm's. My guess it's just a "jumper" tool to reset and initialize the keys to the new unit. So looked into it and saw a yt video of someone jumping 4 and 13 with ignition on for 30 mins, going to try that.

Jumping pin 4 and 13 won't help on a 99. This procedure is to "handshake" a replacement ecu with the immobilizer ecu in the later models.

 

[kevgentile]

Jumping pin 4 and 13 won't help on a 99. This procedure is to "handshake" a replacement ecu with the immobilizer ecu in the later models.

Ah, good to know. Thanks for that bit of info.

So my question then is how would the original ecm, as well as the replacement that the owner provided with the truck, lose communication with the keys?

Is the only way to move forward to send the ecm out to start fresh?

Thanks

 

[Mauser]

Ah, good to know. Thanks for that bit of info.

So my question then is how would the original ecm, as well as the replacement that the owner provided with the truck, lose communication with the keys?

Is the only way to move forward to send the ecm out to start fresh?

Thanks

Did you try the jumper wire in the fuse box with both ecus? The original ecu should still have the key info stored.

What is the ecu part number?

 

[kevgentile]

Did you try the jumper wire in the fuse box with both ecus? The original ecu should still have the key info stored.

What is the ecu part number?

I did run the jumper with the both ecu's. Now the security light flashes with key out too, didn't do that before. But still no steady light.
With the relay in place, no MIL function and no connection to data link. MIL functions with jumper lead from F to +.
Getting a really poor connection at a/b efi fuse. Have to really move it around to get a voltage reading which tells me that a/b is about fried.

With the jumper lead in place, ran diagnostics but states the immobilizer is not installed?

Both ecu's have the same part number 89661-60610. The previous owner sent me the invoice of the ecu purchase from Flagship One Computers. They state that is is a "plug and play" unit.

Just want to confirm the jumper pin out. The owner of the shop I work at thinks that the relay pin 'F' ( top right connector looking from front of the engine) is wrong.

 

[kevgentile]

Confirmed that neither ecu immobilizer functions properly with jumper.
I can scan engine diagnostics but the body modules are giving errors while trying to read out.

Now getting ecu fault for unmatched key code and ecm malfunction (p1633 elec throttle) in one of the units.

Still digging

 

[kevgentile]

You may have seen this already. This test will not work for you if your key is not working or programmed properly. @Mauser will be able to help you with resetting ECM and program new keys.

Yeah, unfortunately it won't work to confirm since the previous owner allowed a lock smith to attempt to hack the eprom.
But the jumper did at least allow me to get power to the ecm to run diag and confirm that the keys aren't being read by the ecm