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Discussion Starter #1
I've noticed lately that my '07 QP Automatic has been pretty far down on power and it inevitably threw a CEL. Subsequently, I bought a Foxwell NT520 scanner (seems to be recommended fairly frequently on here) to pull some details on the codes.

Here some of the codes that are listed as either "Active" or "Stored" in the system:

B1012 - DTC—EEPROM ERROR (Active)
C1557 - DTC—POWER MANAGEMENT UNIT A DI RISVEGLIO (Stored)
C1202 - DTC—FRONT LEFT-HAND SOLENOID VALVE (Active)
U1600 - DTC—BUS CAN OFF (Stored)
B1032 - DTC—FRONT PASSENGER WEIGHT SYSTEM (Stored)

Anybody had any experience with any of these? The car has also had problems starting when hot (starter won't engage) and also made an awful noise last time I started it cold.
 
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None of those are powertrain code so that wouldn't explain your power loss...I would just clear them all and see what returns...You will generally get all kinds of fault codes out of a car if you do a quick test of all the modules...Some are glitches and some are caused by low battery voltage at some point....Jason
 

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Discussion Starter #3
None of those are powertrain code so that wouldn't explain your power loss...I would just clear them all and see what returns...You will generally get all kinds of fault codes out of a car if you do a quick test of all the modules...Some are glitches and some are caused by low battery voltage at some point....Jason
Thanks for the quick reply Jason. I actually ran another test to see if I could pull anything else, and the laundry list got much longer and makes more sense. The car seems to also lose power the further I drive it. After a cold start, it seems to gain some power back. I replaced the battery about three weeks ago.

P0300 DTC--GENERIC MISFIRE (Active)
P0301 DTC--CYLINDER 1 MISFIRE (Active)
P0303 DTC--CYLINDER 3 MISFIRE (Active)
P0302 DTC--CYLINDER 2 MISFIRE (Active)
P0128 DTC--THERMOSTAT TEMPERATURE [PLAUSIBILITY] (Active)
P1602 DTC--PERMANENT POWER SUPPLY [BELOW THRESHOLD] (Stored) *Seems to support your battery theory?
P2234 DTC--LH UPSTREAM LAMBDA SENSOR SHORTED WITH HEATER [SHORT CIRCUIT] (Stored)
P1570 DTC--IMMOBILIZER [PLAUSIBILITY] (Stored)
P1015 DTC--INTAKE CAMSHAFT AND LF MAIN BEARING CRANKSHAFT CORRELATION [SIGNAL] (Stored)
P0907 DTC--TIP FAILURE ERROR SIGNAL [SHORT CIRCUIT TO BATT VOLTAGE] (Active)**
**Triggered "Transmission Failure" light, I presume.

I will clear the codes and take the car on a drive tonight to see what pops back up.
 
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That P1015 code is the reason the car is down on power...The camshafts don't advance when you have that fault and you lose a lot of mid-range torque...Drive it and see what returns...Jason
 

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Discussion Starter #5
That P1015 code is the reason the car is down on power...The camshafts don't advance when you have that fault and you lose a lot of mid-range torque...Drive it and see what returns...Jason
Drove the car about 35 miles (all Interstate) and the CEL returned. Several of the same codes including cylinders 1-3 misfires and P1015. I seemed to have more low-end power before P1015 popped back up, but I could be wrong.
 

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Are the misfires on the same cylinders? You will notice miss fires very quickly.
Could be maf sensor if the misfires shift cylinders. See if you can live monitor it.
The heat could be killing the sensor and when cold be ok until it completely fails.
 

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Discussion Starter #7
Are the misfires on the same cylinders? You will notice miss fires very quickly.
Could be maf sensor if the misfires shift cylinders. See if you can live monitor it.
The heat could be killing the sensor and when cold be ok until it completely fails.
Yep, misfires are on the same cylinders. I'll take the car out either later today or tomorrow and use the reader as a live monitor.
 

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Discussion Starter #8
That P1015 code is the reason the car is down on power...The camshafts don't advance when you have that fault and you lose a lot of mid-range torque...Drive it and see what returns...Jason
Are the misfires on the same cylinders? You will notice miss fires very quickly.
Could be maf sensor if the misfires shift cylinders. See if you can live monitor it.
The heat could be killing the sensor and when cold be ok until it completely fails.
Have not been able to export and compile the live data from the reader yet, but after about an 80 mile drive, the only related trouble codes are P0300, P0301, and P0303. P1015 and P0302 did not reappear.

The further I drove, the less low-end torque I seemed to have. After a cold start though, some of that power comes back.

CEL flashes maybe 10-15 times, remains solid for a little bit, then begins flashing again.

There's also a loud knocking sound for maybe 1 second after a cold start. Could I be looking at a timing chain or variator issue?
 

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You getting only 1 and 3 missing not the whole bank (i.e. 1,3,5,7). Swap the coils and see if it follows the coil.

Can your scan tool read cam angle or timing advance?
 

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Discussion Starter #10
Swapping the coils as we speak.
My scanner puts ignition timing advance anywhere between -10 and 36 over the course of about 10 mins of driving.
 
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You getting only 1 and 3 missing not the whole bank (i.e. 1,3,5,7). Swap the coils and see if it follows the coil.

Can your scan tool read cam angle or timing advance?
Few thoughts..Ignition timing issues or a MAFS problem doesn't make a car misfire on 2 cylinders...I would not drive the car with a flashing check engine light as it could result in the cats melting down...Jason
 
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Are the misfires on the same cylinders? You will notice miss fires very quickly.
Could be maf sensor if the misfires shift cylinders. See if you can live monitor it.
The heat could be killing the sensor and when cold be ok until it completely fails.
:rolleyes:
 
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Discussion Starter #14 (Edited)
Few thoughts..Ignition timing issues or a MAFS problem doesn't make a car misfire on 2 cylinders...I would not drive the car with a flashing check engine light as it could result in the cats melting down...Jason
Yes, my thoughts exactly. That is why i asked about timing and cam angle to pinpoint variators and cam sensor reading. If it was variator i would expect the whole bank would be affected.

And yes do not drive the car with misfires.
Alright, I'm stumped. I disconnected the battery, cleared the codes, swapped the coil packs with cylinders 6, 7, & 8 and drove the car over 100 miles last night (at least 50 on windy back roads). However, I got no CELs at all in that time. I seemingly had at least most of my power back as well.

I also disconnected the variator solenoids for about 20 of those miles just to see if I could get the startup noise to go away. Obviously, that triggered two open circuit codes, but that CEL went away as soon as I stopped an reconnected them.

I drove the car to the office this morning and again got no misfires and no noises from the variator at start-up. I'm honestly shocked. Makes no sense to me. There's no way it'll remain in proper order considering I didn't "fix" anything at all.

Could disconnecting and reconnecting the battery have done it? I know that's typically the "Italian fix-all", but I'm struggling to understand how exactly that would help in this case. Lol.
 

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You may still have some oil in the camshaft caps from your drive. Let it sit for another day or so and see if the startup noise returns. Not sure about the other codes.
 
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It probably didn't fix it and most likely it will come back at some point...Cars just do crazy things occasionally...Jason
 
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I'm not sure that is gonna fix it...Do you feel it missing with a flashing check engine light? Jason
 
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I think I would take the car to a professional at this point...Coils and spark plugs don't really do ok for 100 miles and then act up like that...Jason
 
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