My wife was driving her Grandmothers 2004 SRX 3.6l Cadillac yesterday and it lost power and the engine died on the highway. I plugged in my code reader and got these codes. Hunted around to get two sensors and installed them this morning (passenger side Bank 1 intake A and exhaust B) It wouldn’t crank still. Checked the grounds, wires and plugs and everything looks good. Also unplugged the driver side camshaft sensors just to make sure I got the right ones and that added bank 2 sensors in addition to these, I plugged those back in. I don’t know what else to try at this point. Anyone got any ideas?

P0343 (pending) - Bank 1 cam A position sensor circuit high
P0368 (pending) - Bank 1 cam B position sensor circuit high

So your reader agrees with me.

These show as pending codes on your reader, so I'm not sure these are related. If they are, they might be symptoms but not causes. In my experience, it is unlikely that both sensors dies at the same time, and then also unlikely that this would have caused it to quit on the highway. If anything, it should have illuminated the check-engine light and then kept driving with reduced output.

Before we get into confusion about what "crank" means, let'* agree on the following scale then describe again:

(silence) = nothing
Turn over = rew rew rew rew or bip bip bip bip depending on your car'* preferred starting melody
Crank = (also) rew rew rew rew or bip bip bip bip depending on your car'* preferred starting melody
Fire = vroom
Start = (also) vroom
Stall = vroom then immediately nothing

Does it turn over or crank, but not fire or start? . . . or does it not even turn over or crank?

Good checks!

Crank sensors go out on these sometimes. Not saying that'* it, but a possibility.

Fuel pumps go out on these sometimes. Not saying that'* it, but a possibility.

Sometimes they run out of gas. Some people get insulted when this is suggested. I'd rather insult someone than troubleshoot an empty gas tank for days.

What does the gas gauge read?

About how many miles do y'all think has been driven on this tank?

How many miles on the car?

How many miles has grandma owned this car?

Does it get regular maintenance?

Any recent trauma such as collisions, damage, major repairs, aggressive driving?

When you turn on the ignition without starting it, does the fuel pump run for a second?

When you crank it, how many RPM does the tachometer show? For this, you might have to turn on the ignition, wait for the self-test gauge sweep to complete, then crank for a bit.

What color is the oil?

What color is the coolant?

“These show as pending codes on your reader, so I'm not sure these are related. If they are, they might be symptoms but not causes. In my experience, it is unlikely that both sensors dies at the same time, and then also unlikely that this would have caused it to quit on the highway. If anything, it should have illuminated the check-engine light and then kept driving with reduced output.”
I erased the codes(it was showing those same P0343 P036 and attempted to start it to the point of rough idle and misfire then engine stopped and reconnected and those show up every time.
Also it did lose power and drive for about half a mile before the engine dying on her. She only tried to restart it twice and called me.


“Does it turn over or crank, but not fire or start? “

yes, it’* turns over, occasionally attempts to start for a couple seconds very very rough with misfire sound right before giving up. Mostly though it just turns over without firing.

“Fuel pumps go out on these sometimes. Not saying that'* it, but a possibility.”
noted


“Sometimes they run out of gas. Some people get insulted when this is suggested. I'd rather insult someone than troubleshoot an empty gas tank for days.”
I appreciate your response and I’m not offended. I’m an industrial controls & plc guy by trade, I don’t work on cars regularly but when I do I don’t usually have this much difficulty figuring it out. Its very possible I’ve overlooked something simple.

“What does the gas gauge read?”
Just over a 1/4 tank

“About how many miles do y'all think has been driven on this tank?”
Just a guess but 250 maybe. She drove it from Charlotte NC and it died at mile marker 2 on 77 south in Columbia SC. Had a little over 3/4 when she left.

“How many miles on the car?”
165k

How many miles has grandma owned this car?
8 years

Does it get regular maintenance?
yes but she rarely drives it, just had the oil changed and it’* a new battery. I did bring the battery home yesterday to charge it because the negative wasn’t connected tight and it wouldn’t turn over at all. I initially thought the battery was just low. It was 66% when I put it on the charger. Charged to 100 overnight, put it back in this morning. I had hoped that would get it to crank but when it didn’t I connected my code reader.

“Any recent trauma such as collisions, damage, major repairs, aggressive driving?”
no

“When you turn on the ignition without starting it, does the fuel pump run for a second?”
I don’t hear anything outside the vehicle when I turn the key on.

“When you crank it, how many RPM does the tachometer show? For this, you might have to turn on the ignition, wait for the self-test gauge sweep to complete, then crank for a bit.”
200-300 roms if it tries to run.

“What color is the oil?”
golden

What color is the coolant?
the GM pink/orange color

Since posting I also checked all the camshaft sensor plug wires. Clamped black to negative on battery and with key on checked the + and signal wires all are 5v
then clamped to positive on battery and checked grounds for each plug they are all 12v.

Thanks for all of the great responses!

From this I gather that:

- it talks to your scanner and it tries to run, so probably not the PCM
- it tries to run so probably not spark plugs, coils, crank sensor, etc.
- the fuel gauge probably reads reasonably accurately enough that it'* not empty when it says 1/4 tank
- the tach works so also probably not crank sensor
- battery is good enough to not be the problem
- engine isn't failed due to neglect

At this point, I'd check fuel pressure. Not hearing the fuel pump at key-on is suspicious, and low fuel pressure would make it run rough and/or not start. If this is not it, the alternatives are much more difficult to diagnose and expensive to repair, so I think fuel pressure is your best next step.

What tests have you done? Exhaust is clear? Fuel pressure?

m

I was able to get it to start for 3-4 seconds a couple times yesterday evening. It appears the timing is off. I’m going to verify fuel pressure and the crank sensor, but I have a feeling the aiming chain may have slipped on bank one camshaft.
Thanks for your help, I’ll let you know how it turns out.

Cool, looking forward to seeing what fixes it!