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Discussion Starter #1
My 2001 Diablo 6.0 vt is miss-firing at low rpm. Its been getting worse. A friend put it on his scanner, but was not sure of the codes, he did clear the existing codes. We did a smoke test, but no vacuum leaks. The engine seems to get hotter than normal. I can borrow my neighbors Snapon Solus scanner but does not have the European option and is not familiar with the generic functions. I am now reviewing online teaching aids for the Solus scanner.

I am also trying to decipher the Check Engine light history. As mentioned on Lamboweb, I turned the key off-on four times to display the codes. This video shows the dash codes flashing:

Diablo Engine Light - YouTube

I'm not sure what it means when both Right & Left flash, would that apply to codes such as the Throttle potentiometer since there is only one. I also see the Left Flashing while the Right ON ?

This what I see flashing, let me know what you think, thanks, Dave:

1) Both L & R flashes 11
2) Right only flashes 2
3) Both L & R flashes 10 ?
4) Left only flashes 2
5) Left flashes 10 times while Right is ON
6) Left only flashes 23 times

From LamboWeb.com:

Number Of Flashes Error Indication
1 Lambda sensor inactive
2 Lambda sensor detected weak fuel mixture
3 Lambda sensor detected rich fuel mixture
4 Timing sensor
5 Engine speed and TDC sensor
6 Engine speed and timing sensor signal wrong sequence
7 Air pressure sensor
8 Battery voltage
9 Coolant temperature sensor
10 Not used
11 Intake air temperature sensor
12 Throttle potentiometer
13 CAN communication link failure
14 Not used
15 Not used
16 Not used
17 Catalyst system efficiency
18 Lambda sensor efficiency
19 Misfire detected
20 Misfire detected
21 Carbon filter washing solenoid valve
22 OBDII system failure
23 OBDII system failure
 

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If you used an OBDII scanner, it should have read out the codes specifically. I never had any luck with those flashes.
 

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Discussion Starter #3
Need Manufacturer Specific code info

As mentioned, my engine is misfiring at 2-3k rpm.
I used a snapon scanner in odb2 mode.
Here are the codes:

P0300 Random Misfire

P1306 Manufacturer Specific

P0307 Cylinder 7 Misfire

P1502 Manufacturer Specific

P0111 Intake Air Sensor

What do you think?
What are the Manufacturer Specific codes?
 

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I'm not finding concrete information on the P1502. In the Audi documentation this fault represents an short in the fuel pump relay circuit.

Try unplugging the intake air temp sensor and then running the car through that 2-3k rpm window. if the sensor is bad, it will affect the fuel trim. By unplugging it you eliminate that input and the ECU then receives a default value and looks to the next sensor for data input.

This is the ghetto way of diagnosing faulty sensors. Basically, if unplugging it makes the car run better there is a good chance the sensor is faulty. If there is no change, there is probably different issue causing a faulty reading or the code for this sensor is residual.

Run the Solus in generic OBD2 mode and you should be able to pull some live data. Check the intake temp reading and try to confirm if it seems like a realistic value.

Otherwise, check the ignition and then fuel supply and quality. Bad plugs, wires, coils and gas are all fairly common issues that will cause misfires.
 

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Discussion Starter #5
Unbalanced Vacuum

Here is an update. I managed to correct the serious misfiring problem.
I noticed the vacuum hose for the fuel regulator was longer that it needed to be. This was because the hoses needed to be cross connected, the left fuel rail needs to connect to the right-side intake manifold. I will make a note of this for when I do my next clutch service, not to repeat.


It was running much better, but still flashed the left MIL, but no longer the right MIL. Then I measured the vacuum at each manifold, and it was unbalanced. Fixed that and now I haven't seen the MIL.


Here is the latest pdf graph of the solus obd2:
http://photos.electronicaircleaners.com/photos/Solus%20Ride%20to%20Work.pdf

I believe there may be too much fuel correction.
Your continued help is much appreciated.
 

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Excellent find. It's helpful to mark the hose and it's matching port with a paint pen while disassembling everything.
Yip! Have to agree there. Even mark the connectors on the car, because allot of them can be swapped in other places easily.
 

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Discussion Starter #9
OBD2 Fuel Trim appears high


Here is the latest pdf graph of the solus obd2:
http://photos.electronicaircleaners.com/photos/Solus%20Ride%20to%20Work.pdf

I believe there may be too much fuel correction.
For comparison I looked at the graph of the fuel trim in my 2008 viper. It peaked at a few percent, not 20% like the Diablo, see pdf. I also noticed there is not much difference between the 1st and 2nd O2 sensors. With the Viper, the 2nd O2 sensor was approx flat, I'm thinking because the 1st catalytic converter has done its job, the 2nd O2 sensor doesn't see the swings. Does my O2 sensor voltages look ok?
 

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P0300 Random Misfire
P1306 Manufacturer Specific
P0307 Cylinder 7 Misfire
P1502 Manufacturer Specific
P0111 Intake Air Sensor
What do you think?
What are the Manufacturer Specific codes?
P1306 = BANK 7/12 RANDOM MISFIRE DETECTED STRATEGY III
P0307 = CYLINDER 7 MISFIRE DETECTED
P1502 = have to believe someone wrote down the wrong code.

The p0307 is the base code and will produce p1306 and p0300.

STRATEGY III = the main hot, acceleration or deceleration open loop map.

As far the secondary o2s, those value, whatever they are, are not used in the adjustment of the fuel delivery - only cat efficiency. And the fact that the codes are coming from map usage indicates that none of the o2 sensor values are relevant i.e. the failure is in open loop mode.

-****
 

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I also have a 2001 that is throwing error codes p0300 p1305 p1306 p0307. At first I thought it was isolated to cylinder 7 but I guess not. I tried everything I can think of (tested spark on all cylinders, replaced fuel inj.,compression, replaced primary oxygen sensors) How do I run this solus live data? Should I be looking into replacing the air temperature sensors?
 

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Discussion Starter #12
I need to clarify that the OBD2 codes are no longer being produced, it is no longer turning on the MIL (malfunction indicator light). I have cleared the codes and they are not appearing. As mentioned previously "Here is an update. I managed to correct the serious misfiring problem. I noticed the vacuum hose for the fuel regulator was longer that it needed to be. This was because the hoses needed to be cross connected, the left fuel rail needs to connect to the right-side intake manifold. I will make a note of this for when I do my next clutch service, not to repeat."

Seems to be running good, but the OBD2 graph shows the fuel trim is high. Also is open loop driving normal. Here is the OBD2 graph PDF. http://photos.electronicaircleaners.com/photos/Solus%20Ride%20to%20Work.pdf

When removing the engine, I tagged all the lines with yellow custom labeled tags (photo below). I think I assumed when making the fuel regulator connections.
 

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Your fuel trims are definitely off, hopefully due to having run the car with the FPR's hooked up wrong. The LT Fuel Trims should be around 1%. You B1 is OK, but B2 is off. For reference, yes, I usually see the S1 & S2 sensor readings to be the same, that is not unusual.
 

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Discussion Starter #14 (Edited)
I also have a 2001 that is throwing error codes p0300 p1305 p1306 p0307. At first I thought it was isolated to cylinder 7 but I guess not. I tried everything I can think of (tested spark on all cylinders, replaced fuel inj.,compression, replaced primary oxygen sensors) How do I run this solus live data? Should I be looking into replacing the air temperature sensors?
You can read your intake air temp sensor with OBD2. I could read the temp in real-time and with the snap-on solus scanner, I could plot the temp on a graph over time, as shown in the pdf. OBD2 seems to report the temp, and if I disconnect the intake air temp sensor on the drivers side of the car, OBD2 would report -20°. If I recall I could disconnect the intake air temp sensor on the other side, and not see any change in ODB2.

I borrow the snap-on solus scanner from my friend. It shows a lot of information for the cars listed in its database OR just the bare minimum in OBD2 mode. I dont thinks its not so necessary to have scanner this expensive for OBD2 use, but it does have the feature record over time, such as a drive to work for me. I downloaded the scanner file to my pc for a bigger view of the charts and to print to pdf. The solus screen snapshot shown below shows the graphing feature with a red circle. I never used a scanner before so I did the snap-on training videos.

I made some extension wires that allowed me to measure the voltage across the temp sensor. The voltage measured 2.5 volts in circuit. The voltage with connector disconnected was 5v. I had tried some other temp sensors, that produced 1.8v and read a high temp in OBD2. The temp sensors I bought had a photo showing a brass part, and the one that arrived was plastic and did not extend as deep. I am back to using with my original temp sensors.

I may have corrected the codes shown below when I balanced my intake manifold air pressure. Though there are now no codes, the chart of the fuel trim is being confirmed excessive (thank you).
 
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