gsxrmike

So I have sorted through most threads related to this however I don't believe they are the same issues I'm having... Here is the symptoms;

First off the engine cranks and doesn't start (with not tach movement on the gauge)
Hooked it up to DIACOM software via laptop and says low voltage on reference 5V (forget the error)
Pop off the Throttle postion sense and measure the voltage, read ~ 1.5V which corroborates what the diacom software showed
Unplugged CAM, TPS, MAP, Crank, and both Knock sensors (All three wire sensors) and problem still exists as in low voltage from the PCM with the sensors unhooked.
Poking and probing around, I probe the Black/pink and the grey wire (both part of the 5V reference system) and I get roughly 2.5 ohm (this is with the harness unplugged from the PCM and all the above sensors unplugged)
ETA on Port side working motor the resistance is around 660ohm with everything plugged in except the PCM

All of the 3 flat connectors look intact and don't look melted at all, as well as the (3) three pin round connectors.

I know there is a GM repair kit for the 3 pin flat connectors because they have an issue, but I can't tell which connector could be the issue.


Any help is appreciated

Mike

Also,
replaced CAM sensor and the motors are 496 MAG HO (first Gen) with roughly 280hrs (scanned)

Edit to add
Took the PCM off problem motor (starboard) and tried it on the Port side and the PCM functioned correctly

AllDodge

iTrader: (1)

When you did this, did you try clearing the code, turn key off, turn key back on and see if its still gone?

Trippin

Sounds like a shorted reference circuit, that could certainly cause a no start condition however I'm more inclined to think another circuit is faulty and has failed in range, like maybe your IAC. They are a consistent issue, the connection will overheat as a result of the IAC failing but not give any indication of it other than random usually unrelated or irrelevant fault codes like "Clnt circuit high" Diacom also has it's limitations, there is no substitute for factory diagnostic equipment.

AllDodge

iTrader: (1)

Just noticed you said 1.5V with sensors removed.
Agree IAC, but the most probable is the water pressure sender on the power steering cooler, then there is also the ECT

BUP

iTrader: (9)

No tach signal PERIOD ??

And where did you buy the cam sensor ? That is the BIG QUESTION HERE ? The first and second GEN cam sensors are NLA the 3 gen and to current are the ones available - under one part number

keep in mind this is a 2002 as I believe ------------- correct ?

I would think by now everyone and their gramma plus persons that never has put a wrench in their hands knows about the IAC for 555 - but will ask --- has the IAC been changed correctly and the related parts ?? Plus has the IAC connector examined & tested closely ???

Are the fuel injectors firing ??

is there fuel at the fuel rail and fuel at the injectors ??

Check all breakers and fuses especially the breaker for the fuel injectors - that one causes a no start because they will fire / flow fuel

- also check for the IAC circuit fuse.

PCM / ECM 555 clearing fault codes nor with MEFI's ECM 's is not with key on / off. Adding info leaving old stored codes has nothing to do with a no start or running conditions. Actually I leave fault codes stored as all fault codes list run times at the actually timeframe they faulted. There is a reason why I leave them stored on PCM / ECM 555. And besides 99 percent of the time your going to have at least 2 to 4 fault codes with PCM / ECM 555 because they are defaulted codes. Pitot - steering - fuel circ - and so on.

I have the early GEN cam sensors all brand new, if you exhausted all the other avenues for the no start condition. Bad and or wrong cam sensor the engine will not start either.

gsxrmike

Thanks all for the help. Most of the things suggested I did try.

the good news is it looks like I was able to solve the issue. It seems that even though I have mechanical trim indicators the harness and transom assembly are wire to accept digital trim indicators. Where this harness plugs into the transom inside the engine compartment, something has failed or shorted out. So unplugging the harness to the transom corrected the issue. So as a point of reference, the 5V circuit also powers the digital trim even though the colors change. For that harness.