[Tahltan]

There is no power going to the cpu.

Turn the key on nothing happens to the dash, lights work, cranks fine.

Brief history as told me:

Running fine, shut it off, was hard too start, ran fine for a few more days, then wouldn't start, 2 days later started went home shut it off was the last time it started. Another mechanic replaced the fuel pump and checked fuses and relays and checked connections with a test light not a voltmeter he came to the conclusion of a burnt cpu

I was asked to install cpu which I did still nothing. I have checked fuses, relays, connections, continutity. I even went so far as to dump a little gas down the throttle body to see if it would fire :p of course nothing:confused:

The cpu is located on DS front fender nest to the power distubation box

My question is:

Were is and is there a fusible link in the system?

Does anyone have a wiring diagram for said year? Will go over and get more info for you if needed.

Any suggestions will be greatly welcome to speed up this repair as it is currently -20C outside.

[TxGreaseMonkey]

. Check all underhood and underdash fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-t...tml#post252145

Be very thorough. The ECM fuse is likely in the underhood fuse box. If you don't have power going through both test points on the top of the fuse, remove the fuse and clean the blades of corrosion, apply a light coating of dielectric grease to the blades, replace the fuse, and test again. It's crucial to obtain power through each test point on the fuse.

I wouldn't worry about fusible links per se. If there is one, it's likely between the ignition switch and the starter motor. Most "maxifuses" (cartridge-type fusible links) are in the underhood fuse box.

. Check for codes.

. Clean main ECM ground.

. Check for 5 volts going to the MAP Sensor connector, when the ignition switch is turned to ON. Red probe goes to the reference wire (likely the one on the right, as you look at the connector), Black probe goes to ground. If you do not record any voltage or it's a fraction of a volt, the ECM is likely bad:

While we find your parts, please enter your ZIP Code at PartsAmerica.com

. Check for spark. If none, replace the Ignition Control Module and coil:

While we find your parts, please enter your ZIP Code at PartsAmerica.com

While we find your parts, please enter your ZIP Code at PartsAmerica.com

. Check for fuel.

[Tahltan]

I have checked the fuses and have power.

Have replaced the ecu

No power to ecu, no self checks no power to fuel pump cranks fine, lights work, nothing on the gauge pack

Waiting on code reader but with no power to ecu will it work?

6 hrs from store, it -20C outside and I have no detailed scymatic of system. Have checked all the grounds I could find all seem good. As for the main ecu ground I have no idea were that is.

[this8384]

What made the mechanic say that the ECM was bad? Have you checked for spark?

[Tahltan]

I have checked everything that I have been able without a proper wiring diagram to follow.

As far as I can tell, there has to be a broken wire or a bad connection somewere in the system. Or the other mechanic fryed something when he used a test light to check for power at the fuel pump. And he is an apprentice mechanic 1rst year.

On his recomenddation the owner ordered the ecu ($180) and he had me install it.

I myself have looked for power every were, good ground and lots of juice up to the power distribution box, have checked fuses with multimeter good have even gone so far as to pull the fuses and inspect each one visiually. Have checked the relays both with meter and swapping with a know good one.

When you turn on the key! There is no ecu self checks no lighst on dash ie: check eng light should come on when eng not running, no gauge movement.

Eng cranks fine lots of spin will not fire. Ecu controls the whole eng right?

Headlights brakes all work but those are different systems.

There are 4 wire connections to the ecu 2 big ones and 2 small ones.

I need the advice of someone that has run into this sort of problem of this year to point me in the right direction.

Lol it is -20C right now and the truck is outside with no shop to pull it into.

Like I said any advice or crazy idea would be greatly appreaciated.

Tahltan