My friends car.
Fuel pressure is 58-60 psi.
the following codes were showing. P0685, P0113, P0341
The Po113 referred to an intake temp sensor which was unplugged and is now plugged in.
Several other codes were written down but not their numbers. owner cleared the codes after the temp sensor was plugged in thinking it might be causing some of the other codes. There are now no codes.
the codes without numbers were all misfire codes. One random and one for each cylinder.
Am I right in thinking that I should start by replacing the CPS?

 

Potentially there are no codes at the moment because criteria for setting them hasn't been met b c the engine has not run long enough in closed loop to collect enough data to figure out what's going on.

Sounds more like a Passlock security system issue. What you described is exactly what happens when the security system is tripped and the car thinks it's being stolen

What is the behavior of the security light on the dash?

1) no key in it, all doors locked.
2) key turned to on position but not crank
3) after cranking and starting and then stalling

Does it blink, is on but goes out, is off but comes on and stays on? That is the level of detail of answers we need to sort this out if it is indeed a passlock issue.

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It is possible that the p0685 code is real. It stands for
ECM / PCM Power Relay Control Circuit Open and set if the voltage and the ECM power relay is detected to be low when it should not be, meaning the relay is open when it should not be.

The PCM ECM get the power they need to run the vehicles electronics through this feed. However the code can't set if the electronics aren't already powered up.

So the ECM cannot request the voltage at the relay because the PCM is not operational because it does not have any current going through that relay so that it can function properly.

Passlock is simple to check and quick to resynchronize if needed. If it is not a Passlock issue, then we chase down the
p0685.

 

I always start with testing. Without testing you are guessing. That's not good.

 

Exactly. That's why I suggested some.

We do not shotgun parts here.
If we don't know the answer we say so. I gave you a simple set of steps to start with. I have no doubt in my mind you will follow through with them. Hopefully the issue is no more serious than that. But as stated above, test before parts swap.

 

Sadly I seem to have been in idiot mode yesterday. I had to move the vehicle forward snd forgot to turn it off and put it in park. Where it sits precludes jump starting it due to access, so I put it on charge and will try again tomorrow.

 

Well, yesterday WAS Monday! LOL

 

After the battery was charged the owner started the vehicle and drive it. 10 to 15 miles later it started stalling again. I just checked the dash lights as instructed above.
off no key doors locked, no lights.
Key on not running all lights come on the go off except oil pressure charge check engine. And for some reason one down in the right bottom of dash showing a wrench and oil can. I assume this means the vehicle wants an oil change.
edit to add. I couldn't get the car to start during this attempt. butbonly tried 3 or 4 times.

 

Thank you.
How about after it is started and immediately stalls.... That is the critical one. We are trying to determine what the security light status is after you crank the engine, the vehicle starts, and immediately stalls. The other two checks were for background so to speak and to see if the car already thought it was being stolen. You would have seen the security light not turn off under those circumstances that you measured.

​​​​​​But we need the one that you did not report, which is car starts but runs for a few seconds then stalls. What is the status of the security light?

Obviously, security system can't have been triggered if the car is being driven around.

However, the system is designed to constantly redetermine the security state the entire time you are driving.. so if you have an intermittent issue, you can be driving down the road, security system can suddenly think the car is being stolen, and it will shut down the fuel injectors and the car will stall. It will then do the start run 2 seconds stall thing. We need to know what the security light is doing during that process.

Please post back at the outcome of that scenario. I have only ever seen that on the forum one other time in over a decade and a half but it is possible.
People trying to diagnose it assume it is not Passlock security, because the vehicle started and ran. And that's true 99.98% of the time. This is the one time it isn't true and is worth checking how the system is behaving after the vehicle stalls while driving or starts and stalls.

 

I will try to start it again today. It failed to fire up at all last night. So I don't have that answer.

 

What does the security light do when you are trying to start and it will not start? That is equally as important in ruling in or out the security system.