Electrical problems

[DavidC]

So if you bump the starter you will have approx. 30 seconds to check across those wires for 12vdc and if not present from the yellow to grnd to rule out a grnd wire issue. I do not know if those wires go directly to the ECM, a splice or a plug.

 

[mbpoindexter]

So if you bump the starter you will have approx. 30 seconds to check across those wires for 12vdc and if not present from the yellow to grnd to rule out a grnd wire issue. I do not know if those wires go directly to the ECM, a splice or a plug.

They go to a plug that is part of the main engine wiring harness.

 

[DavidC]

Should be able to check there.

 

[mbpoindexter]

So I have since changed the lift pump and redone the wiring correctly through a relay. I also changed the throttle position sensor as it was under warranty, so why not.

I took the truck out for a drive. I get a fair bit of white smoke until we are close to operating temperature then I don't get any.

I will have P0073 and P0107 immediately after resetting the codes regardless. Instant. But im not really worried about those codes at the moment.

Drove truck for about 45 minutes. I drove truck back to house to check if any new codes had come up after driving around, no new codes just those same 2. However, when I lay into the throttle going up a hill it caps me out at 2k RPM and kinda stumbles like it preventing me from going over that.

But the worst part is as soon as I started it back up, the throttle stopped working again. No codes for TPS or APPS. No P2509.

I can't figure out this stupid throttle problem.

Also, something I have just noticed is that in the FSM and in other videos the 2005 truck has the pedal APPS. My truck has the style in the 03-04 models with the sensor kind of above the CP3 inside the throttle body.

 

[sag2]

The 5v supply for the APPS and the Inlet air/Pressure sensor are not the same. You really need to correct the P0073 and the P0107 before you go any further. The diagnostic for both the codes is not that difficult. Since it is two sensors in one, it more than likely is a problem with one of the common circuits, the 5v supply or the sensor ground. It would seem pretty slim that both sensor signal circuits failed at the same time.

 

[mbpoindexter]

The 5v supply for the APPS and the Inlet air/Pressure sensor are not the same. You really need to correct the P0073 and the P0107 before you go any further. The diagnostic for both the codes is not that difficult. Since it is two sensors in one, it more than likely is a problem with one of the common circuits, the 5v supply or the sensor ground. It would seem pretty slim that both sensor signal circuits failed at the same time.

What do you mean 2 sensors in 1? I thought the P0107 code was for the MAP sensor on the intake manifold and the P0073 was for the inlet air sensor on the intake before the turbo? Is that wrong?

The MAP sensor at the intake manifold is brand new and I have the sensor before the turbo coming in the mail next week. Should there be a constant 5 volt supply to the sensor at the intake filter before the turbo? I asked this question several times in a different forum and no one gave me an answer. Is it that all of the sensors should have 5v?

Thanks Sag

 

[mbpoindexter]

The 5v supply for the APPS and the Inlet air/Pressure sensor are not the same. You really need to correct the P0073 and the P0107 before you go any further. The diagnostic for both the codes is not that difficult. Since it is two sensors in one, it more than likely is a problem with one of the common circuits, the 5v supply or the sensor ground. It would seem pretty slim that both sensor signal circuits failed at the same time.

With engine turned off that voltage to the pre turbo MAP sensor is 12.6 in 2 of the 4 pins.

This is not the same with the intake MAP sensor, with engine and key off there is no voltage to that sensor in any pin.

 

[sag2]

With engine off no 5v circuit should have any voltage. If it does you have a short to voltage on those circuits. Here is the wiring diagram for the sensor. Disregard the splice on the 5v as this is from the 2006 CD service manual. Your 2005 should not have the splice.

 

[mbpoindexter]

With engine off no 5v circuit should have any voltage. If it does you have a short to voltage on those circuits. Here is the wiring diagram for the sensor. Disregard the splice on the 5v as this is from the 2006 CD service manual. Your 2005 should not have the splice.

Sag,

I have 4.95 volts between pins 1 and 3 from your diagram 5v supply and sensor ground. So seems right.

If i test pins 1 and 3 from battery I get the 12.5 v. For example, black cable to pin 1 or 3 and red cable to positive battery post. This should show 12.5v right?

 

[mbpoindexter]

This is the next step in troubleshooting. from FSM.

While monitoring scan tool, use a jumper wire to connect the (K690)
Return circuit to the (K616) signal circuit at the Inlet Air Pressure sensor
harness connector.
Does the scan tool show a P0107 Inlet Air Pressure Sensor Low
DTC.
Yes >> Replace the Inlet Air Temperature/Pressure sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE - DIAGNOSIS
AND TESTING)
No >> Go To 4

So if I understand, connect pin 1 and 4 with something, can I use a paperclip? I will not do anything until you confirm.

 

[sag2]

Sag,

I have 4.95 volts between pins 1 and 3 from your diagram 5v supply and sensor ground. So seems right.

If i test pins 1 and 3 from battery I get the 12.5 v. For example, black cable to pin 1 or 3 and red cable to positive battery post. This should show 12.5v right?

I don't understand your comment that you get 12.5v when checking pins 1 and 3 to battery. Why are you checking those to battery? If you have 5v between pins 1 and 3 you just confirmed your 5v and the sensor ground are good. No need to check anything further on those circuits.

 

[mbpoindexter]

I don't understand your comment that you get 12.5v when checking pins 1 and 3 to battery. Why are you checking those to battery? If you have 5v between pins 1 and 3 you just confirmed your 5v and the sensor ground are good. No need to check anything further on those circuits.

Just out of curiosity. I'm trying to find anything electrically odd that may cause weird electrical problems.

Can you confirm my comment about connecting pins 1 and 4 in previous reply?

 

[sag2]

Also if you are front probing the pins you need to be very careful not to damage the terminals. Especially the ECM terminals. I never probe straight in to a terminal. I always try and come in at an angle from the side and lightly touch the terminal with a fine wire probe.
And yes, you can use a paper clip to short the two circuits together, but I prefer a light ga wire (like 18-20) so there is no chance to spread the terminal.

 

[mbpoindexter]

Also if you are front probing the pins you need to be very careful not to damage the terminals. Especially the ECM terminals. I never probe straight in to a terminal. I always try and come in at an angle from the side and lightly touch the terminal with a fine wire probe.
And yes, you can use a paper clip to short the two circuits together, but I prefer a light ga wire (like 18-20) so there is no chance to spread the terminal.

Just want to make sure I'm doing this right.

First, erase codes then With key off, connect pins 1 and 4 with paperclip or something skinnier if i can find it. Then turn key to on, see if code is present.

Is that right?

And if code is present the FSM says replace sensor.

 

[sag2]

What the test is trying to prove out is if the fault goes from a P0073 to a P0072 when you jump the air pressure sense circuit to ground. If it does, it proves out the circuit and the ECM is capable of seeing the difference between an open circuit/short to B+ and a grounded circuit.

 

[mbpoindexter]

What the test is trying to prove out is if the fault goes from a P0073 to a P0072 when you jump the air pressure sense circuit to ground. If it does, it proves out the circuit and the ECM is capable of seeing the difference between an open circuit/short to B+ and a grounded circuit.

Sorry,

I thought we were going after P0107. The P0073 code first asks to test for resistance, which I will do now.

However if i do connect pins 1 and 4 I still get the same codes. No change

 

[sag2]

Here is another diagram that might help. Again it is from 2006 Service Manual PDF but should be close.

 

[Ozymandias]

If you have the engine mounted apps then your truck is an 04.5 with the 600 engine. I've never heard of a true 05 with this setup.

Does your transmission have the stepper motor or still the TV cable?

 

[mbpoindexter]

If you have the engine mounted apps then your truck is an 04.5 with the 600 engine. I've never heard of a true 05 with this setup.

Does your transmission have the stepper motor or still the TV cable?

TV Cable. I'm sure its not a true 05 at this point.

I can't get these damn codes to clear P0073 and P0107. Im assuming it is a code coming from the sensor mounted on the intake air filter before the turbo, right?

It has to be electrical because the codes won't clear with a DTC reader, right? If I clear codes with DTC reader, they are immediately there again.

The wires are in good shape, sensor is brand new, I don't get it. 90% of the info on these codes is either solved by replacing sensor or people just forgot to plug it in.

Also, this little code reader INNOVA 3100 j+, it has a freeze frame thing. If I reset codes with ignition on and reread those 2 codes come back. In the freeze frame for P0107 it says MAP 25 (inHg) and IAT 90 (degrees F). It is currently like 54 degrees, so its like its getting the signal becuase there is data there but its not correct, does this give anyone some clues?

 

[mbpoindexter]

I am working through the troubleshooting for code P0107 from 2005 FSM. It says solve other codes first, however I have measure voltage from pins 3 and 4 which should be k668 (5 volt supply) and Y502 (return circuit). I have 0 volts.

Is voltage between 4.5 and 5.5v?
No -> go to 5.

Measure resistance between pins 1 and 3 (K668 5v supply) and (Y502 return circuit).

Resistance is less than 100k which indicates a short.

Am I doing that correctly?