98 Tahoe computer?

[caw333]

How can you tell If the computer is bad without buying another one. Is there a place that can test them. Can just part of it go bad or does the whole thing go bad.

[16th hippy]

one little circuit in the PCM can be bad, keep truck from running, and rest can be perfect. give us some more info. year, make, model, engine, symptoms, and so on. maybe just a bad dist cap, maybe bad PCM. let us know what's going on.

[MT-2500]

Originally Posted by caw333

How can you tell If the computer is bad without buying another one. Is there a place that can test them. Can just part of it go bad or does the whole thing go bad.

The VCM/PCM very seldom goes bad.

A good repair shop or dealer can run a test with a scanner check on the computer will tell you if most of the stuff is working right in it.
Has the check engine light been on or blinking?

As 16th hippy says we need more info.
Give him some good info.
What is it doing or not doing?

[caw333]

I've been chasing the problem for a month or so now and I'm running out of ideas. Its a 98 chevy tahoe 4x4 with a 350. It's running but it runs rough and starts to backfire after 30 or so seconds. I've got the code po341 camshaft position sensor. I've replaced it twice just to make sure but still throwing same code.I've changed plugs,wires, cap, rotor, crankshaft sensor, maf sensor and camshaft sensor. Checked to make sure I'm getting power at sensor and it was good. The only thing I can find out of the ordinary is on the computers white plug there are two pins on the bottom right side with black wires that look like they got hot. The wires look alright though. I'm running out of ideas and things to change out. Thanks for any info.

[MT-2500]

Code 341 points to cam/crank sensor wiring problem.
Any add on electrical stuff?
Hi amp high fi or two way radio or bad plug wire interference.
Any electrical wiring repairs or charging voltage oir battery problems on it?

If wire has been hot to VCM check out the circuits the wire go to and the plug in and terminals.

What is the pin no of wiring on hot or burnt wiring?

[777stickman]

The input from the CMP to the VCM goes thru connector C1 (blue) pins 3 & 8.

Pin 3 is BRN/WHT wire and pin 8 is PNK/BLK.

The diagnostic aids for P0341 point to possible electromagnetic interference from after market equipment, harness routed too close to the High Voltage side of the dist, harness routed too close to relays or solenoids and/or shorted or open wiring in the circuit.

With the engine running, move the engine harness at various locations. If the RPM's change while doing this you may have found the problem area.

[caw333]

The two pins that got hot are on white harness pin # 17 & 18 Both black and white stripes.

[MT-2500]

Originally Posted by caw333

The two pins that got hot are on white harness pin # 17 & 18 Both black and white stripes.

Pin 17-18 both are black and white ground wires going to the cylinder head.
Make sure the ground is good there.
Also all other grounds.
If you lose a ground someplace it can overload other grounds.
Strange that the grounds wires would get hot.
Some scanners show the computer or case case ground reading.
Good luck.