Hey everyone

I’m having a really tough time with my 2006 Hummer H3 (3.5L). The engine cranks normally, but it just won’t start and I’ve been chasing this issue for a while now without much luck.

Here’s what I’ve done so far:

Timing chain is in correct position, verified, no signs of jumping or slack.

No spark and no injector pulse during cranking.

Replaced both the camshaft (CMP) and crankshaft (CKP) sensors, multiple times, with known good sensors.

Wiring to both sensors checks out, good continuity, clean connectors, no corrosion.

All fuses and relays are intact and tested good.

ECU has power and grounds are solid.

The only code I’m getting is P0341 – Camshaft Position Sensor Range/Performance, and it stays even after all the above.

Scanner used is Autocom (generic OBD), which shows basic info but doesn’t give full GM-specific data.


The issue is I’m based in Europe, and over here, parts for the H3 are hard to find, and not many people are familiar with this engine or platform. No dealership support either, so I’m stuck relying on online info and the community.

At this point, I’m wondering, could this be an ECU fault? What else could cause both spark and fuel to be disabled, along with a persistent P0341?

 

Passlock issue?

Aftermarket Alarm?

 

Fuse box.... scanner Danner and bro did a really indepth video of a fuse box interior failure for a H3.

 

Problem solved. It turned out to be a faulty intake camshaft sensor. The previous shop told me it had already been replaced a couple of times, so I didn’t bother changing it again. Just two days ago, I found out they never actually replaced it at all.

 

Congrats on the happy ending.