Electrical problems

[Ozymandias]

P0073 on mine is the ambient air temp sensor, that one is in the grille a side from the left head light.
P0107 is the MAF just at the air filter unit.
Both deliver temp info to the ECM,if they are off, then both codes show up.

If yours is a 04.5 you might should use that manual for trouble shooting.

 

[cerberusiam]

P0073 should be the intake air temp on the pre-turbo TQ tube. It does communicate with the MAP and cause dual errors. Check and make sure it is plugged in tight and the wires are not pinched anywhere.

Check your build date on the driver door for actual MY so you are sure what you have.

 

[sag2]

I looked again at the service info for the p0073 and it's a bit confusing. One code says it's for the ambient air temp sensor which would be the one by the grill and another procedure for the same code says it's the Dual sensor that would be on the air cleaner. Probably need to check the wire colors against the truck to make absolutely sure you're working on the correct sensor. Without looking back at the service information you're generally going to check for the voltage. If you don't have it you're going to look for an open circuit, short to ground, short to voltage, or the two wire shorted together.
If you are missing the five volt, check from the 5 Volt to battery ground. If you still don't have it you've at least eliminated the sensor return being missing. Sensor return as just a clean ground that is through the ECM versus going direct to battery.

 

[mbpoindexter]

Hi guys,

Im sure that the sensor on the air intake filter is causing these problems. It causes both codes.

Here is where I am at.

Troubleshooting for code P0073. I was doubting my skills at connecting wires through this troubleshooting process but now I am certain in the result.

I had infinite ohms between K615 at sensor connector and ecm connector and infinite ohms between K616 and ECM connector. I did not think this was right. So, I know I have a 5v supply there so I connected K668 (5v supply) at sensor connector and I went through every single pin in both C1 and C2 looking for resistance. I got 3 ohms at pin 25 in C1. I still was not sure so I connected K690 (ground) at sensor connector and tested every single pin in C1 and C2 ECM connectors and got 3 ohms at pin 29 in C1. These 2 are where they are supposed to be.

I then connected K615 and tried every single connector pin in C1 and C2. Never got any ohm reading.

I then connected K616 and tried every single connector pin in C1 and C2. Never got any ohm reading.

This confirms that those 2 returns do not connect back into ECM connector, or that there is a break in both returns somewhere. Correct?

Please someone confirm.

 

[sag2]

You must have broken wires, as those two circuits do go directly to the ECM, specifically C1, pins 13 and 16.

 

[mbpoindexter]

You must have broken wires, as those two circuits do go directly to the ECM, specifically C1, pins 13 and 16.

I understand they should go back to pins 3 and 35 in C2. This is consistent between both 2004 and 2005 diagrams.

Can you confirm?

 

[mbpoindexter]

I understand they should go back to pins 3 and 35 in C2. This is consistent between both 2004 and 2005 diagrams.

Can you confirm?

2006 I see pins 13 and 16 like you mentioned in C1

 

[mbpoindexter]

I pulled up C2 and looked at pins 3 and 35. Colors match violet and white for both C2 pin 3 and sensor connector pin 2.

ECM connected 2 pin 35 is brown and yellow this is also the color of the wire coming from pin 4 on the sensor connector.

Rechecked again the ohms, I get infinite for both. Has to be a break somewhere. But I think this is very odd to have a break, as I cannot find anything with 1 foot of the sensor.

 

[sag2]

If you have confirmed the wire colors at the sensor and ECM and they match the diagram, use a T-pin and tap into the wire a few inches from the ECM first, then check continuity between the T-pin and the ECM terminal. If you have continuity between those to points add a second T-pin near the sensor and check continuity between the sensor terminal and the T-pin. If your good there add a jumper wire between the T-pins and see if the one code will clear.

 

[Ozymandias]

Check also that the pins are properly seated inside the C1/2 connectors.

 

[mbpoindexter]

now computer cant connect to read codes for some reason.....

 

[mbpoindexter]

guage cluster not moving at all when i bump key. Speedometer, battery, rpm, fuel gauge, oil pressure all at 0. Where could I have hit something? Does that communication for the cluster come from the ECM or the fuse box?

 

[sag2]

Are you sure you have been very careful removing/reinstalling the ECM plugs? It almost sounds like the terminals are not making connection at the ECM. That would not explain nothing in the cluster when you turn the key to run position. The cluster should power up regardless if the ECM is connected or not.

 

[mbpoindexter]

Are you sure you have been very careful removing/reinstalling the ECM plugs? It almost sounds like the terminals are not making connection at the ECM. That would not explain nothing in the cluster when you turn the key to run position. The cluster should power up regardless if the ECM is connected or not.

I am sure I was careful.

I used a T-tap and checked both wires at both connector ends (sensor and ECM). The break is in the middle of the wire in the harness somewhere because when I do the resistance from the T-tap about 3 inches downstream of the sensor I get 0 ohms from both wires at the sensor as well as about 1 inch upstream of the ECM plug, same thing. So they are contacting at the plug.

However I checked the battery volts and all the work ive been doing without running alternator they were down to 12.1v.

I'm hoping that has something to do with the cluster. So they are charging now.

However if you read before I did have this same cluster problem, with the following codes:

P1652 – J1850 communication Bus – guage cluster dies

P2509 – ECM/PCM input signal intermittent

I thought the cluster dying was a result of the P2509 code, which I thought I fixed by cleaning batteries and cleaning all grounds.

However, the cluster is still down this morning unfortunately so i still can't check codes. Really hoping its a battery voltage issue but im skeptical. This truck is such a nightmare.

 

[mbpoindexter]

I also check pins 21, 49, and 50 in C2 while troubleshooting p0073 and p0107 with a test light to make sure ECM grounds were viable. All 3 lit up no problem.

I'm looking at the FSM for codes P2509 just to be sure and also P1652. Troubleshooting steps are quite short and simple. I'm praying it has to do with battery voltage....

 

[Ozymandias]

Disconnect both batterys after they are charged, switch on ign. to discharge ever capacitor in it, reconnect battery's, reboot the system that way.

A test light around an ECM is a big no-no.

 

[mbpoindexter]

Disconnect both batterys after they are charged, switch on ign. to discharge ever capacitor in it, reconnect battery's, reboot the system that way.

A test light around an ECM is a big no-no.

I didn't know that. Why is that? too much voltage?

 

[mbpoindexter]

Batteries at 12.8v all gauges stuck at 0. Cant read codes.

Unreal...

 

[mbpoindexter]

Alright, back to square one it seems.

Cluster works, when i do the reset everything on the dash has power and moves like it should.

C-code list:
0d 38
64 38
81 00

AB 19
AA 00

AF 00

Any ideas? going to check what these mean on FSM.

I understand the 00 means done so it seems like there are 3 lists but I don't know what these 3 lists mean, does anyone? ECM PCM and something else, maybe?

Also, last time cluster didn't work it eventually came back by itself and i pulled that code form before P1652

 

[Ozymandias]

I didn't know that. Why is that? too much voltage?

A test light takes way more power then the board can withstand. In general on every electronic circuit a test light is not to be used. You can use an electronic probe for this.

Simple said, a 1$ test light can easily fry electronics for thousands of dollars within a blink of an eye.