1979-1993 & 94 Conv [Subscribe to Daily Digest] |
![]() | [Main C900 Bulletin Board | BBFAQ |
Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: overboost switch vs. overpressure sensor Posted by Justin VanAbrahams [Email] ![]() ![]() In Reply to: Re: overboost switch vs. overpressure sensor, tsw, Wed, 17 Jan 2007 10:23:11 Members do not see ads below this line. - Help Keep This Site Online - Signup |
The Saabsite referring to the pressure transducer as an "overpressure sensor" is a complete misnomer, and not consistent with any of Saab's terminology. The picture and part number they show is for a pressure sensor (or pressure transducer, which is not only what it really is but what Saab calls it). The purpose of this sensor is to provide feedback to the APC control unit telling it what the current boost pressure is. It does not, in any way, have anything to do with an "overpressure" function. In fact, it's entire purpose is to let the APC control unit respond gradually to increasing boost pressure to *avoid* an overpressure scenario. Bypassing it completely defeats the purpose of the APC system, and will either result in a permanent base-boost scenario, or a permanent unlimited boost scenario. You don't want either - the sensor must be there, functioning, correctly installed.
The overboost switch (also Saab's terminology) kills power to the fuel pump when it's triggered by excessive boost pressure and restores power when boost returns to a safe level. When it fails, it will often fail in the "closed" position, killing power to the fuel system. This sensor can be easily, and often safely, bypassed. On an LH 2.4 car like yours, it doesn't exist.
posted by 207.15.18...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
![]() |
![]() |
![]() |
![]() |
![]() |