Multiple strange errors

[nonickatall]

Hi,

I recently bought a Cadillac Escalade with the 6 Liter machine. The car has an LPG Gas unit. The car runs absolutely well, no shaking of the machine, it has power. I guess the fuel consumption is a bit high, I didn't expect 19 liters per 100 kilometers, when driving restrained but i don’t know if this is too high.

The car was last week at the German TÜV, which is a regular check up, including a check up of the exhaust gas which was good.

Last week, I drove for a while and parked the car. I wanna start the car again and the motor lamp comes immediately. There was no change in the performance of the engine. After I switched off the engine and parked the car overnight, the engine lamp was still on, the next morning.

So I read out the error codes and had the code:

P0455 DTC StatusCurrent DTC
Last TestFailed
This IgnitionNot Ran
MIL Requested
Since ClearedFailed

Whatever this means?!

As well, I had a lot of other errors

P0101 mass air flow Sensor performance
P0108 manifold absolute pressure sensor circuit high voltage
P0128 engine coolant temperature below Thermostat regulating temperature
P0131 HO2S circut low voltage Bank 1 Sensor 1
P0132 HO2S circut high voltage Bank 1 Sensor 1
P0133 HO2S slow response Bank 1 Sensor 1
P0134 HO2S circut insufficient activity Bank 1 Sensor 1
P0138 HO2S circut high voltage Bank 1 Sensor 1
P0140 HO2S circut insufficient activity Bank 1 Sensor 1
P0141 HO2S Heater Performance Bank 1 Sensor 2
P0151 HO2S circut low voltage Bank 2 Sensor 1
P0152 HO2S circut high voltage Bank 2 Sensor 1
P0153 HO2S slow response Bank 2 Sensor 1
P0154 HO2S circut insufficient activity Bank 2 Sensor 1
P0155 HO2S Heater Performance Bank 2 Sensor 1

Because I didn't know if these were old errors, I deleted all errors. The engine lamp was off. I drove for several days without problems. Yesterday I had the same issue again. After driving where everything was okay, I parked the car short, started the engine again and the engine lamp was on again, and didn't switch off until I deleted all errors again today.

After I deleted the codes this time, I started the engine again and checked for Error Codes again.

All codes immediately return, except:

P0455 DTC StatusCurrent DTC
Last TestFailed
This IgnitionNot Ran
MIL Requested
Since ClearedFailed

which seems to cause the engine lamp to light.

Does anybody has an idea where to start looking for problems,?
Because I don't think that my:
Airflow Sensor, my MAP Sensor, the coolant temperature, both Ho² Sensors are bad, but my Car runs good and had last week no issues at the exhaust gas check.

Excuse my bad English , I am from Germany.

Best regards and many thanks in advance

Ralf

 

[nonickatall]

My own research brought me to the possibility that the EVAp system has a problem, that is the code P0455..

I found this very help full Video concerning the fundamental function of the system, which give me the possibility to look for the problem myself.

Does anybody knows if the other errors are probably subsequent errors?

 

[Fless]

Most of those codes are related to the MAF and the oxygen sensors. I would say to clean the MAF (with MAF cleaner) and check and clean any and all engine and body grounds, as well as have the battery load-tested. I would also check that the engine coolant is warming up to 200 or 210°F. A scanner can tell you what the engine coolant temp is reporting, and you can verify that the engine is getting to full temp by putting a hand on the main radiator hoses to see how hot they feel, or using an infrared temp sensor.

The EVAP cycle won't run unless specific criteria are met: engine cold; engine coolant temp within x°F (9°? 15°? I forget) of intake air temp, fuel tank level between 1/8 and 7/8, as well as a few more.

 

[rockola1971]

Well there is one ive never seen before. A LPG Esky! Didnt know they even made them. Wonder if they were only made for the european market?

 

[Tonyrodz]

Well there is one ive never seen before. A LPG Esky! Didnt know they even made them. Wonder if they were only made for the european market?

Pretty sure I've read it's a popular conversion in Europe due to the price of gas there. They also charge by the litre, not by the gallon.

 

[nonickatall]

Hi,

Yes, LPG gas is in Europe pretty common. A gas system costs about 3.000€ when you install it new, for a car like the Escalate. I is not original from Cadillac, its a manufacture, which is called Prins, which is the market leader in LPG systems for cars. Your fuel consumption increase about 15%, but the price per liter for gasoline is at the moment about 1.90 Euro and LPG is about 1.05€ So when i drive 15,000km per years, i save about 700€ per year. So i looked for an Escalate with a LPG system. But that problem is not coming from the LPG system. I am sure. The LPG System was in Inspektion about 6 Month ago and work without errors.

What I wonder is the following: Maybe someone can say something about..

I use a Chinese device to read the OBDII codes. This device contains all cars of the world and is mostly very helpful. What is new at GM, which I never seen at another manufacture is, I have two sections where errors are stored, like you see on the attached pic.

One is "Current&History DTC(s)" where i have the error which comes from the EVAP system and which lights the motor lamp.
And another section, which is called "Additional DTC(s)", is where i have the rest of the errors.

My guess is, that the Chinese guy, who programmed the software, made a mistake in translation and these are historical errors, because if the Mass Air Sensor, the MAP and all Oxygen Sensors would not work proper, I should have a bad running engine and I could for sure, not pass the emission test last week. And as well, a non-working mass air sensor should result in a luminous engine lamp, but it doesn’t. And there is as well the error with the coolant temperature. Today I looked at that. The motor temp is after a few kilometers on 100° Celsius (about 212° Fahrenheit) which is middle of the gauge. So i think that should be ok..

What do you think?

 

[nonickatall]

The EVAP cycle won't run unless specific criteria are met: engine cold; engine coolant temp within x°F (9°? 15°? I forget) of intake air temp, fuel tank level between 1/8 and 7/8, as well as a few more.

That explains why the error only occured twice. Both times short after i switched on engine, when it was running 5 minutes ago..