AU: 2009 Q5 2.0L petrol, where is the after-run pump relay?
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AU: 2009 Q5 2.0L petrol, where is the after-run pump relay?
Replaced the pump but there's no power, checked all fuse box, driver and passenger sides, back of car and ECU bay, replaced all fuses, but there's no power.
Where is that relay?
please
Where is that relay?
please
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Joined: Dec 2001
Posts: 13,997
Likes: 3,376
From: Georgia
One has to wonder why the J496 is marked as optional equipment. But also, is your CDNx engine stop/start enabled? If so, the correct wiring diagrams section is 76, not 5. Though the wiring of the J496 is the same in both.
Still, you have the wiring diagrams document, so if you just search on J496, you eventually come to section 803 that shows where it is in the ECM box. But, interestingly, the footnote says "only for 6-cyl gas". That's because for the 4-cyl, apparently it should be called the J151. Yet another Audi split brain fault. J151 or J496, it's in that E position. The E position is a 10-pin plate for two half sized "404" relays, not the larger cube relays. For me, it's on the side towards the car center.
So that there's no power at the V51 (which is a 2-pin unmanaged pump for B8.0, so the power delivery is managed via a relay; B8.5 version is a 3-pin and is directly controlled) is perfectly fine, unless you know the J623 ECM is specifically activating the V51. Which wouldn't be the case unless you had a hot engine you just turned off. Because the V51 pumps against the direction of normal flow when the engine is running.
Still, you have the wiring diagrams document, so if you just search on J496, you eventually come to section 803 that shows where it is in the ECM box. But, interestingly, the footnote says "only for 6-cyl gas". That's because for the 4-cyl, apparently it should be called the J151. Yet another Audi split brain fault. J151 or J496, it's in that E position. The E position is a 10-pin plate for two half sized "404" relays, not the larger cube relays. For me, it's on the side towards the car center.
So that there's no power at the V51 (which is a 2-pin unmanaged pump for B8.0, so the power delivery is managed via a relay; B8.5 version is a 3-pin and is directly controlled) is perfectly fine, unless you know the J623 ECM is specifically activating the V51. Which wouldn't be the case unless you had a hot engine you just turned off. Because the V51 pumps against the direction of normal flow when the engine is running.
Thread Starter
AudiWorld Member
Joined: Aug 2024
Posts: 386
Likes: 31
One has to wonder why the J496 is marked as optional equipment. But also, is your CDNx engine stop/start enabled? If so, the correct wiring diagrams section is 76, not 5. Though the wiring of the J496 is the same in both.
Still, you have the wiring diagrams document, so if you just search on J496, you eventually come to section 803 that shows where it is in the ECM box. But, interestingly, the footnote says "only for 6-cyl gas". That's because for the 4-cyl, apparently it should be called the J151. Yet another Audi split brain fault. J151 or J496, it's in that E position. The E position is a 10-pin plate for two half sized "404" relays, not the larger cube relays. For me, it's on the side towards the car center.
So that there's no power at the V51 (which is a 2-pin unmanaged pump for B8.0, so the power delivery is managed via a relay; B8.5 version is a 3-pin and is directly controlled) is perfectly fine, unless you know the J623 ECM is specifically activating the V51. Which wouldn't be the case unless you had a hot engine you just turned off. Because the V51 pumps against the direction of normal flow when the engine is running.
Still, you have the wiring diagrams document, so if you just search on J496, you eventually come to section 803 that shows where it is in the ECM box. But, interestingly, the footnote says "only for 6-cyl gas". That's because for the 4-cyl, apparently it should be called the J151. Yet another Audi split brain fault. J151 or J496, it's in that E position. The E position is a 10-pin plate for two half sized "404" relays, not the larger cube relays. For me, it's on the side towards the car center.
So that there's no power at the V51 (which is a 2-pin unmanaged pump for B8.0, so the power delivery is managed via a relay; B8.5 version is a 3-pin and is directly controlled) is perfectly fine, unless you know the J623 ECM is specifically activating the V51. Which wouldn't be the case unless you had a hot engine you just turned off. Because the V51 pumps against the direction of normal flow when the engine is running.
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Joined: Dec 2001
Posts: 13,997
Likes: 3,376
From: Georgia
The two 404s together are the starter relays. The relay relevant to the V51 pump is the one that's by itself. Which side of that dual relay plate it needs to be in, it's the relay 2 position according to the wiring diagrams. You should see on the relay plate 1/2/3/4/5 for relay 1 and 12/22/32/42/52 for relay 2. (so "x" and "x2")
You should be able to validate 12v to the 12 and 32 positions, but only with ignition on, possibly necessary for engine on, depending on how that ECM is programmed to control the J271 relay. The 12v comes from fuse 7 in that panel, which powers many things on the engine, and is itself powered by the J271 relay (term 87), not the battery direct (term 30) or the ignition relay (term 15). And continuity from the 52 position to the pin 1 at the harness connector to the V51 pump. Pin 2 of the harness connector to the V51 pump goes to chassis ground. Position 22 is the control line from the ECM to energize the relay and pass 12v from the fuse 7 to the V51 pump. Again, this would occur only at engine off, as the pump direction is opposite of that during normal engine operation.
The J271 relay is that 643 cube to the right of the J496 aka J151 solo half relay. The 643 at the far right next to the starter relays is the J757 relay.
You should be able to validate 12v to the 12 and 32 positions, but only with ignition on, possibly necessary for engine on, depending on how that ECM is programmed to control the J271 relay. The 12v comes from fuse 7 in that panel, which powers many things on the engine, and is itself powered by the J271 relay (term 87), not the battery direct (term 30) or the ignition relay (term 15). And continuity from the 52 position to the pin 1 at the harness connector to the V51 pump. Pin 2 of the harness connector to the V51 pump goes to chassis ground. Position 22 is the control line from the ECM to energize the relay and pass 12v from the fuse 7 to the V51 pump. Again, this would occur only at engine off, as the pump direction is opposite of that during normal engine operation.
The J271 relay is that 643 cube to the right of the J496 aka J151 solo half relay. The 643 at the far right next to the starter relays is the J757 relay.
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Thread Starter
AudiWorld Member
Joined: Aug 2024
Posts: 386
Likes: 31
The two 404s together are the starter relays. The relay relevant to the V51 pump is the one that's by itself. Which side of that dual relay plate it needs to be in, it's the relay 2 position according to the wiring diagrams. You should see on the relay plate 1/2/3/4/5 for relay 1 and 12/22/32/42/52 for relay 2. (so "x" and "x2")
You should be able to validate 12v to the 12 and 32 positions, but only with ignition on, possibly necessary for engine on, depending on how that ECM is programmed to control the J271 relay. The 12v comes from fuse 7 in that panel, which powers many things on the engine, and is itself powered by the J271 relay (term 87), not the battery direct (term 30) or the ignition relay (term 15). And continuity from the 52 position to the pin 1 at the harness connector to the V51 pump. Pin 2 of the harness connector to the V51 pump goes to chassis ground. Position 22 is the control line from the ECM to energize the relay and pass 12v from the fuse 7 to the V51 pump. Again, this would occur only at engine off, as the pump direction is opposite of that during normal engine operation.
The J271 relay is that 643 cube to the right of the J496 aka J151 solo half relay. The 643 at the far right next to the starter relays is the J757 relay.
You should be able to validate 12v to the 12 and 32 positions, but only with ignition on, possibly necessary for engine on, depending on how that ECM is programmed to control the J271 relay. The 12v comes from fuse 7 in that panel, which powers many things on the engine, and is itself powered by the J271 relay (term 87), not the battery direct (term 30) or the ignition relay (term 15). And continuity from the 52 position to the pin 1 at the harness connector to the V51 pump. Pin 2 of the harness connector to the V51 pump goes to chassis ground. Position 22 is the control line from the ECM to energize the relay and pass 12v from the fuse 7 to the V51 pump. Again, this would occur only at engine off, as the pump direction is opposite of that during normal engine operation.
The J271 relay is that 643 cube to the right of the J496 aka J151 solo half relay. The 643 at the far right next to the starter relays is the J757 relay.
