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Ron, ASE Certified Technician
Category: Dodge
Satisfied Customers: 36065
Experience:  ASE Certs
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I have a 2008 Dodge Magnum with a 2.7L engine with. P0038

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I have a 2008 Dodge Magnum with a 2.7L engine with. P0038 code on bank 1, sensor 2 (downstream). We replaced the O2 sensor. CEL still on. There is no power to the sensor from the pcm, but there is continuity from thepcm to the O2 sensor. Is this a pcm problem or something else?
JA: Is the power loss consistent, or does it fluctuate?
Customer: Mostly constant with a lack of power, but it does fluctuate at higher speeds
JA: Are you fixing your Magnum yourself? What have you tried so far?
Customer: Yes - so far the initial codes were P0420 and P430. I replaced all of the sensors. Then came up with the P0038 code. Then started checking for power to the hewed circuit and then the continuity check.
JA: Anything else you want the mechanic to know before I connect you?
Customer: It didhave an extension on both down stream sensors which I did not replace.

Hello. My name is ***** ***** I am happy to assist you today. Give me just a moment to review your post, and I'll be right back with the help you need.

Reference voltage come from the PCM to the HO2S sensors and on bank 1 sensor #2 the power feed at the PCM is pin 17 (Brown/violet) . Is that the wire and pin your checking?

Customer: replied 1 month ago.
Customer: replied 1 month ago.
No not yet

Okay that in most cases means the problem is with the PCM if the wire ohms out okay. That being said I would go back and recheck it once more to be sure with the factory steps I have enclosed in the link below. If you find the same results then suspect the PCM.

Customer: replied 1 month ago.
Thanks. I will go back and re-verify per the instructions.

I would just to be sure. Thank you as well. Please take a moment to rate my service so I can get credit for my time, the question remains open for follow up even after doing so, all you need to do is return to this question if need be.

Thank you again.

Ron and 8 other Dodge Specialists are ready to help you
Customer: replied 1 month ago.
Ron, where is the z902 wire and/or connected? I seee a z904 on the wiring diagram but not the 902 wire.
Customer: replied 1 month ago.
Do you have the pcm verification test noted in the PDF?

The Z904 is the Ground 109 located at the shock tower, see the location in this link.

Customer: replied 1 month ago.
Thank you once again.Ok here goes. I cleaned the ground at z902 and it is 12.9 v to the battery positive.The voltage at k299 pin wa 2.19mv.There was no resistance between the k299 and the z904 on the O2 heater circuit.Do you think this is the pcm?BTW - this vehicle passed smog in May. When we bought it a week ago the CEL was not on. Then it came on with a 420 nad 430 code, The only changes made since then that I know of is rpelacement of the O2 sensors which included an adapter of sorts on the down stream sensors that is intended for high performance headers. I did not replace the adapters because they were stripped out.
Customer: replied 1 month ago.
1.19 mv at k299 not 2.19 mv

From reading your results and providing you have done your testing right it sure dose look like the PCM is at fault here.

Customer: replied 1 month ago.
Ok thank you.One more question off the beaten path. There is an open connector (2 prong) on the back of the engine that doe s not seem to have a home. The wire harness seems to go to the back of the engine block. Any idea what this is.

Unfortunately with out being have to have a look at it I do not know where it would go. It could just be a connector for something your car is not equipped with.

Customer: replied 28 days ago.
Thanks for the follow up. Based on pour help nad assistance, we have ordered a PCM and we awaiting arrival.That said, I know I am on a 7 day trial. At this time, I do not want to extend to a full or more permanent membership. Thanks for the offer, but I prefer to use your resources as needed in the future. Thanks.

I have no control over what type of plan you have. You will need to contact customer support for any questions you have on this . Thank you as well.

Customer: replied 25 days ago.
Ron,Looking at a wiring issue with a couple of open wires in the engine compartment. My shop manual does not have the engine harness. There are two wires that are opened up and have been spliced but are not connected to anything. There is also that open plug discussed earlier.My question is do you have a wiring diagram for the engine harness that you can send to me.Thanks again for your help.

Chrysler only offers wiring for the circuits and dose not offer any for the Harness as a whole. If you know the circuit I can provide a wiring diagram.

Customer: replied 25 days ago.
One is the camshaft sensor.The one with the open wires some out of the same harness as the mass air flow sensor, but not sure what circuit. I think hate in-used plug that comes from the back of the engine is the abs circuit, but that is a guess based on a picture you sent last week.
Customer: replied 25 days ago.
Thank you

Your very welcome and thank you as well.

Customer: replied 16 days ago.
Good afternoon Ron,We got a reman PCM and now the vehicle has three codes (P0038, P0340, and P0344) the two new ones are camshaft sensor and/or wiring which makes sense because the vehicle is hard starting with a long crank. Not sure why the old PCM did not pick it up.I have replaced both camshaft sensor and crankshaft sensors, as well as validated continuity of the wire harness to the PCM. However, the wires to the crankshaft sensor are not where the wiring schematic said they should/3 on the PCM C2 connector. So, I am confused. Any ideas with this limited information?

One other cause for the cam codes your getting to set can be cause by cam timing, are you sure the timing is aligned correctly and your chain has not jumper?

Customer: replied 16 days ago.
Would get engine still run ok with the mechanical timing off a notch? Because the. Engine runs real smooth.

In most cases it would not. If you did not have these codes before the ECM replacement them I would wonder if the replacement PCM is defective.

Customer: replied 16 days ago.
I am sure it is possible, but the vehicle did pick up power and runs much smoother with the exception of the codes referenced. For all intents, I feel the pcm is good, no real solid answer as to why except my gut. Instinct.

If you clear them out do the return?

Customer: replied 16 days ago.
Is the s110 contact point a ground. The camshaft sensor appears to not be grounded. There are three wires, a power which is yellow and pink, and a blue & Grey and a blue and green. The blue and green goes to s110 which I assume is ground????

Splice S110 is the ground supplied to the sensors from the PCM See the link below for the wiring diagram.