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crushing Vs with my Wurm
2013 GT500 - 700+ HP
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12,266 Posts
Discussion Starter #1
Fellas,

Took the V in for the SES light and heres what it spit out.

P0101 maf
P0420 cat
P0886
P1626
C0241
U1016

Now I get the Cat issue, I used cheap gas when I was in the boonies and it was a 10% ethanol mix. WIth the StealthV tune, that would cause a lean condition. I have driven that tank out...Im more curious about the ABS codes and the Maf code...
How about a little help on what the codes are, technically and what suppositions you may have.

Thanks for the help.

F
 

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FAQ is your Friend
CTS-V
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3,987 Posts
did you look those codes up?

http://www.cadillacfaq.com/faq/answers/dtccode.html

One is the theft module related to gas delivery.... Could be a fluke communication issue... Did you clear them and they re-appeared?

how did you retrieve the codes?

Reed
 

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crushing Vs with my Wurm
2013 GT500 - 700+ HP
Joined
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12,266 Posts
Discussion Starter #3
went to the dealer and had em pull em via Tech2. Looking to buy EFILive or HPtuners though so I can do it myself. Thanks for the link.

F
 

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226 Posts
DTC P0101
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The powertrain control module (PCM) uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle condition. A large quantity of air entering the engine indicates an acceleration or high load condition. The MAF sensor has the following circuits:

• An ignition 1 voltage circuit

• A ground circuit

• A signal circuit

The PCM applies a voltage to the sensor on the signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies within a range of near 2,000 Hertz at idle to near 11,500 Hertz at maximum engine load. The PCM uses the following sensor inputs to calculate a predicted MAF value:

• The manifold absolute pressure (MAP) sensor

• The intake air temperature (IAT) sensor

• The engine coolant temperature (ECT) sensor

• The engine speed (RPM)

The PCM compares the actual MAF sensor frequency signal to the predicted MAF value. This comparison will determine if the signal is stuck based on a lack of variation, or is too low or too high for a given operating condition. If the PCM detects the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value DTC P0101 sets.

Conditions for Running the DTC
• DTCs P0102, P0103, P0106, P0107, P0108, P0120, P0220, P0442, P0446, P0449, P0455, P0496 and P2135 are not set.

• The engine is running.

• The ignition 1 signal is between 11 and 18 volts.

• The throttle position (TP) indicated angle is less than 95 percent.

• The change in the TP indicated angle is less than 5 percent.

• The MAP sensor is more than 17 kPa.

• The change in the MAP sensor is less than 3 kPa.

• The above conditions are met for 1.5 seconds.

Conditions for Setting the DTC
The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4 seconds.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
• The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
• Inspect the harness of the MAF sensor to verify that it is not routed too close to the following components:

- The secondary ignition wires or coils

- Any solenoids

- Any relays

- Any motors

• A low minimum air rate through the sensor bore at idle or during deceleration may cause this DTC to set. Inspect for the following conditions:

- Any deposits on the throttle plate or in the throttle bore

- Any vacuum leak downstream of the MAF sensor

• Inspect for any contamination or debris on the sensing elements of the MAF sensor.

• Inspect the air induction system for any water intrusion. Any water that reaches the MAF sensor will skew the sensor and may cause this DTC to set.

• Inspect the secondary air injection system (AIR) for any water intrusion.

• A wide open throttle acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 5-12 g/s at idle to 200 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.

• Inspect for a skewed or stuck ECT sensor.

• A high resistance of 15 ohms or more on the ignition 1 voltage circuit may cause the DTC to set. A high resistance may cause a driveability concern before this DTC sets.

• The barometric pressure that is used to calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running the BARO value is continually updated near wide open throttle. A skewed MAP sensor will cause the calculated mass air flow value to be inaccurate and may result in a no start condition. The value shown for the MAP sensor parameter varies with the altitude. With the ignition ON and the engine OFF, 101 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.

• A high resistance on the low reference circuit of the MAP sensor may cause this DTC to set.

• A short to voltage on the 5 volt reference circuit of the MAP sensor may cause this DTC to set.

If the condition is intermittent, refer to Intermittent Conditions .

Test Description
The numbers below refer to the step numbers on the diagnostic table.

This step will determine if the MAP sensor pressure is within the proper range for a given altitude.

This step will determine if the MAP sensor voltage is within the proper range at idle.

This step will determine if the MAP sensor responds properly to the change in manifold pressure.

This step will determine if the throttle position (TP) sensors are operating properly.

This step will determine if any mechanical faults have caused this DTC to set.

This voltage drop will determine if high resistance has caused this DTC to set.
 

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crushing Vs with my Wurm
2013 GT500 - 700+ HP
Joined
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12,266 Posts
Discussion Starter #7
CTSVONFIRE,

I hope you didnt type that! Thats a TON of verbage...thank you though for the info.
Its weird, theres nothing to indicate why ANY of those codes got posted. Maybe a freak elex storm...

F
 

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Cadillac Technician
none
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11,051 Posts
P0101 means that the calculated value for the operating conditions you are under do not match the actual sensor reading. That means if you have more or less airflow than calculated the code will set. Mods and programming can affect this easily. If it's running okay you probably have a calibration issue if this code sets regularly.

P0420 means you have a bad catalyst, period. The O2 sensors have to pass the test before a 420 diag will run, that means they are testing good and the catalyst is not. You may have poisoned the cat, which has a longer than regular warranty on it because it's emissions equipment, however if you go in with a bunch of mods they may deny the warranty on the cat saying you killed it by making modifications.

I suspect what you have as a P0886 is actually a sloppliy written (by them) P0336. That is usually related to the crankshaft or "CKP" sensor.
Possible harness issues, EMI or even a failing sensor can generate this code.
Terminal contact is also an issue, although I haven't had to go after this code on a V yet.

P1626 is a theft deterrent system code. How often do you have starting problems? This might be related to other issues, but I'd almost have to have the car to play with and know the history of this particular code to go after something. If you have reprogrammed the PCM this could be where the code originated also. Programming wreaks havoc on CTS and sets all kinds of crazy codes.

C0241 has to do with the torque requested circuit from the PCM to the EBCM. They tell eachother what is going on as far as delivered and actual torque for traction control and ABS functions. At some time one of them didn't talk or lied. This too would require duplication or more research.

U1016 is a communication code. Whatever module had it stored lost communication with the PCM. The U means communication, the 1 designates this as a GM specific DTC and the 016 identifies the module which the other module can't see. This might be related to the theft problem but barring that possibility most U codes are only there to confuse you, not literally of course but sometimes they can lead you astray.
 

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FAQ is your Friend
CTS-V
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3,987 Posts
ewill3rd said:
P0101 means that the calculated value for the operating conditions you are under do not match the actual sensor reading. That means if you have more or less airflow than calculated the code will set. Mods and programming can affect this easily. If it's running okay you probably have a calibration issue if this code sets regularly.
P0420 means you have a bad catalyst, period. The O2 sensors have to pass the test before a 420 diag will run, that means they are testing good and the catalyst is not. You may have poisoned the cat, which has a longer than regular warranty on it because it's emissions equipment, however if you go in with a bunch of mods they may deny the warranty on the cat saying you killed it by making modifications.
I suspect what you have as a P0886 is actually a sloppliy written (by them) P0336. That is usually related to the crankshaft or "CKP" sensor.
Possible harness issues, EMI or even a failing sensor can generate this code.
Terminal contact is also an issue, although I haven't had to go after this code on a V yet.
P1626 is a theft deterrent system code. How often do you have starting problems? This might be related to other issues, but I'd almost have to have the car to play with and know the history of this particular code to go after something. If you have reprogrammed the PCM this could be where the code originated also. Programming wreaks havoc on CTS and sets all kinds of crazy codes.
C0241 has to do with the torque requested circuit from the PCM to the EBCM. They tell eachother what is going on as far as delivered and actual torque for traction control and ABS functions. At some time one of them didn't talk or lied. This too would require duplication or more research.
U1016 is a communication code. Whatever module had it stored lost communication with the PCM. The U means communication, the 1 designates this as a GM specific DTC and the 016 identifies the module which the other module can't see. This might be related to the theft problem but barring that possibility most U codes are only there to confuse you, not literally of course but sometimes they can lead you astray.

Damn... Nice one Ewill!...

On the theft module code: did you have the Valet switch option installed (stealthV tune?)... could be realted maybe...
On P0336: Did you set your CKP... Ever run the car without the PCM in it (using another PCM...)?
On U1016: 016 is the PCM from what I see...



Reed
 

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crushing Vs with my Wurm
2013 GT500 - 700+ HP
Joined
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12,266 Posts
Discussion Starter #13
Thanks guys for the 411. I can think of 2 instances where there might have been some issues.
1. I helped a stranded traveller by giving a jump start. Maybe this gave some voltage issues?
2. I used some garbage gas out in the boonies that would help explain the cat issue.
I do have the StealthV tune, but its been 20K miles now...no issues. Maybe a CPK relearn is in order. Anyone help me get a deal on HPTuners or LS1Edit?

F
 

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The diagnostic system on cars today is set up for the car as it comes from the factory. If you change anything, there is a possibility that the diagnostic system will think that there is a problem and produce a DTC. Actually it is very likely that any changes will produce DTCs. My CTS-V is completely stock except for a power connection for the radar detector made at the fuse block under the rear seat. I have never seen any DTCs (I have an Actron 9145 to read the codes). This includes the DTC that I am sure was produced when one of the TPMs failed. The technician who replaced the TPM reset the DTC when he programmed in the new TPM. Moral - either don't change anything or don't worry about the DTCs if you do. You can change things and possibly reprogram the diagnostic system to account for the changes, but I don't know of anyone who knows how to do this.
 

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crushing Vs with my Wurm
2013 GT500 - 700+ HP
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12,266 Posts
Discussion Starter #15
I think that getting some software to see what it is will put my mind at ease. It was a freak incident. I have put on 500 miles since those codes and not one was set since. If the cat was toast, there would be a new DTC set by now. Thanks for the help.

F
 

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2005 CTS 3.6L, 2006 350Z, Ducati 996s
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Guys, whats the significance of the codes, in relation to what I should do about them? Now, obviously some of the codes will be different on our vehicles, as I'm a 3.6L. But they still moean problems or potential issues right? Well, I looked at my codes, and theres about 10 thrown, the same ones there before I broght it in to get serviced.
Should these codes have been cleared?
The ones I have now, should they indicate problems?

thanks for any help, guys!
 

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Cadillac Technician
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Sometimes techs forget to clear them when they are done doing the work. It's dumb not to because if the car comes back you don't know if you fixed anything or not really. Fortunately for PCM codes you have freeze frames to look at. They usually have mileage when the code set and how many times it's set. That can tell you if it was before the last visit or since the last visit. Most on board systems don't capture freeze frame data however so it can leave you stumped on problems that may have already been fixed.
It's possible for the codes to return but if they weren't cleared it can sure cause a headache.

Bear in mind that there are many thing that can trigger codes, not limited to simple system hiccups. U codes I usually ignore unless it's related to a complaint on the repair order, and some other codes as well. Sometimes all they do is lead you astray.
The best thing to do if you have codes that are history, is write them down, clear them and drive the car to see if they come back.

As a side note, if the P0420 has not reset, the catalyst may have been effected enough to fail the diagnostic but whatever made it do that could have burned away and hopefully didn't leave anything behind that could actually damage the catalyst bed.
 
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