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Hello all, I've had a few Saab's over the years but I could use some help on this one. The intermittent code I'm getting is for fuel rail pressure sensor circuit high. about every 10-15 starts or so it just cranks as if a no fuel issue but after a few tries it finally starts no problem. Sometimes it throws an engine light sometimes not. It seems to mainly happen after a 10-15 minute drive after the engine warms up good. Tech tool said most common fix is fuel pressure sensor so I replaced. Didn't solve the issue. Next was fuel pump however it looked like PO had recently done it as the bolts and hardware looked cleaned/fresh etc. Next was the 3 wire connector to the fuel pressure sensor replaced and that didn't solve either. So now I'm stuck I can't find any info on alldata to keep going. This is a well kept Saab with 102k miles. Don't want to give up on her. Any help would be much appreciated. Thanks in advance.
 

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The only other things in the fuel pressure control loop are the ECU and the PWM driver for the fuel pump. It's possible there's an intermittent in the wiring.
 

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Check that the fuel pressure sensor isn’t on to tight. Over tightening will cause issues.
 

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Discussion Starter #4
The only other things in the fuel pressure control loop are the ECU and the PWM driver for the fuel pump. It's possible there's an intermittent in the wiring.
Do you know where I could find a diagram for this?
 

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I have a similar intermittent P0193 code being thrown. Had the code with the OEM pump. Replaced pump and still got intermittent code. Car runs and starts great even with code present. Replaced FPS with new Bosch FPS. No change. If car sits overnight no code thrown. If restarted with engine at normal operating temperature, code will be thrown more often but not all the time. Seems to be more prevalent on extremely hot days. Since the fuel system on the 2.8L is a non-return system, could the pressure of the fuel in the fuel rail raise above spec due to engine and ambient heat soak? I have a fuel pressure test set, as I havebeen unable to find a repair manual to cover my 2008 9-3 Aero with the 2.8L V6 could anyone tell me what the spec is for fuel rail pressure and what pressure will throw the P0193 code. Also wondering if fuel tank evaporation system could be causing increase in fuel pressure on hot days?
 
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Hello all, I've had a few Saab's over the years but I could use some help on this one. The intermittent code I'm getting is for fuel rail pressure sensor circuit high. about every 10-15 starts or so it just cranks as if a no fuel issue but after a few tries it finally starts no problem. Sometimes it throws an engine light sometimes not. It seems to mainly happen after a 10-15 minute drive after the engine warms up good. Tech tool said most common fix is fuel pressure sensor so I replaced. Didn't solve the issue. Next was fuel pump however it looked like PO had recently done it as the bolts and hardware looked cleaned/fresh etc. Next was the 3 wire connector to the fuel pressure sensor replaced and that didn't solve either. So now I'm stuck I can't find any info on alldata to keep going. This is a well kept Saab with 102k miles. Don't want to give up on her. Any help would be much appreciated. Thanks in advance.
I have a 2008 9-3 Aero 2.8l with the same exact problem. Replaced fuel pump and pressure sensor. No change. Saab mechanic recommended replacing fuel pump again with a OEM Saab pump. Order it through Saab OEM USA. They canceled order due to many returned defective pumps. I can’t believe that all of the reported P0193 codes are caused by defective pumps. Hard to believe that all the various mfg of pumps can’t makr them perform. My P0193 was present with the OEM and Carter replacement pump. There has to be something else going on. If anyone finds the magic fix let us know. Can’t believe we need to hand pick fuel pumps. An interesting test I performed was to hook up a fuel pressure gauge to a warmed up runny engine. Turned off the key and watched the pressure go from 40 psi to 70 psi within 5 minutes due to heat soak. With Saabs closed system I wonder if during hot restarts the pump kicks on and causes the intermittent P0193 code. I never get the code on a cold engine and the car runs great with/without code.
 

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I believe this fault cannot be due bad pump, the pump must generate more than 150psi for such a code to appear and those pumps are totally incapable to do so.
That leave the following
Sensor.
Sensor ground.
ECM.

so if u replaced the sensor with a new OE Bosch, it is mostly eliminated .
I would check the sensor ground if it is steady, try to move the wiring harness, maybe look at the pressure reading on the scantool while wiggling the harness and most important the connector itself.

after u eliminated all, that leaves one possibility, ECM .
 
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I believe this fault cannot be due bad pump, the pump must generate more than 150psi for such a code to appear and those pumps are totally incapable to do so.
That leave the following
Sensor.
Sensor ground.
ECM.

so if u replaced the sensor with a new OE Bosch, it is mostly eliminated .
I would check the sensor ground if it is steady, try to move the wiring harness, maybe look at the pressure reading on the scantool while wiggling the harness and most important the connector itself.

after u eliminated all, that leaves one possibility, ECM .
Thanks. I have a bad feeling that my and other Saab owners who are going crazy with the intermittent P0193 and no-start problems will find that the ECM is being cooked by the high engine heat. The highest pressure that I've seen on my mechanical fuel pressure gage is 72psi after the hot engine sits for 15-20 minutes. The only thing that still stumps me is that when I get a no-start on a hot engine, I bleed a very small amount of pressure from the fuel rail and the car starts immediately. Car runs great with/without P0193 code. If I didn't like the AERO so much I'd sell it but it's just too much fun to drive.
 

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How about when u have a no start, compare gauge reading to sensor reading ..
Has anyone found a reliable fix for this? I have a 2007 Aero with same issue. Trouble starting warm engine. 2 new fuel pumps, new pressure sensor and issue remains.
 

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Has anyone found a reliable fix for this? I have a 2007 Aero with same issue. Trouble starting warm engine. 2 new fuel pumps, new pressure sensor and issue remains.
Maybe fuel pump control module is bad?
 

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Thanks. I have a bad feeling that my and other Saab owners who are going crazy with the intermittent P0193 and no-start problems will find that the ECM is being cooked by the high engine heat. The highest pressure that I've seen on my mechanical fuel pressure gage is 72psi after the hot engine sits for 15-20 minutes. The only thing that still stumps me is that when I get a no-start on a hot engine, I bleed a very small amount of pressure from the fuel rail and the car starts immediately. Car runs great with/without P0193 code. If I didn't like the AERO so much I'd sell it but it's just too much fun to drive.
This sounds like vapor lock. Gasoline can boil as low as 37°C/100°F depending on blend and conditions. A thermal barrier might help on fuel rail and fuel line to rail.
 
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