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2001 SLS
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10 Posts
Discussion Starter #1
my 2001 sls has left me stranded twice now. im leaning towards fuel pump but not sure. If the car is pointed down hill and ideling the fuel pressure drops to 10lb and the car wont run. I can cost down to the flats and it will start up. Fuel regulator seams to be ok. On the level ground ive got 40lb of fuel preasure and its regulating like it should. Also when i shut the car off i loose fuel preasure. Dont have any rubber lines to pinch off so im not sure where it goes.no noticable leaks anywhere. I thought i was out of gas the first time but it does this with a full tank.The regulator showes no signs of leaking case or vacumn. Theres a leak somewhere but if it was in the tank why do i loose preasure with a full tank of gas
open for sugestions
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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71,095 Posts
It is normal for rail pressure to slowly bleed off at Engine: OFF If you habitually run the fuel level below 1/4 then it's possible that the pump is losing prime. Normal pressure is 41 - 47 at idle or just after Key: ON.

If the pressure bleeds off rapidly at Key: OFF on level ground then then the check valve in the pump assembly is sticking open.

There is an access port in the trunk floor, just forward of the spare tire well.

Fuel pump assembly DELPHI.jpg
 

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Super Moderator
2003 Deville Base
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5,445 Posts
not sure about your model, but some tanks have "anti-slosh" baffles, and they are known to come loose, letting fuel slosh to one side/end and starving the pump. Does this happen when you have a full tank?
 

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2001 SLS
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10 Posts
Discussion Starter #5
yes.At full tank. I pulled in and filled up and it only held 3 gal. Also gas gage doesnt work correctly. Ive had several GM cars and the gage acts up before the pump quits.But this time the pump is quiet and holds 40lb preasure unless its headed down hill
 

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2001 SLS
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10 Posts
Discussion Starter #6
i have another issue that i just realized i have. Dont think it has anything to do with the fuel pressure drop.. I cant go in reverse. When i shift into reverse the engine sputters and dies. i can go forward but not backward. I have a p741 code and i thought i fixed that. The switch on the brake peddle was loose and telling the brain i had applied the brake disconnecting the lockout. but it must be the silonid. That wouldnt have anything to do with the fuel,would it. I no the fuel preasure drops when pointingdown hill and i no the pump will pump 40lb+.
 

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Super Moderator
2010 DTS
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87,572 Posts
P0741 has nothing to do with fuel. It is there because the PCM has detected a little slippage in the TC above the allowed limits (couple hundred RPM). It is not caused by the brake pedal switch. It is a leaky internal seal.

 

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2001 SLS
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10 Posts
Discussion Starter #8
Im monitering fuel pressure. AT key on engine off i have 40lb of fuel pressure. With the engine running it goes to 38lb
. When i put the shifter in reverse my fuel pressure drops to 0lb and the engine dies. I can go forward but no fuel pressure in reverse. Something is turning the fuel pump off when i shift into reverse. not sure where to start. I also loose fuel pressure when the car is headed down hill.On level ground the pressure is good. Regulator seams to be working. Pressure goes from a stead 38 to 40 when i rev the engine then settles back to 38lb. could this be tied to the p741 code?
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
Joined
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20,253 Posts
Im monitering fuel pressure. AT key on engine off i have 40lb of fuel pressure. With the engine running it goes to 38lb
. When i put the shifter in reverse my fuel pressure drops to 0lb and the engine dies. I can go forward but no fuel pressure in reverse. Something is turning the fuel pump off when i shift into reverse. not sure where to start. I also loose fuel pressure when the car is headed down hill.On level ground the pressure is good. Regulator seams to be working. Pressure goes from a stead 38 to 40 when i rev the engine then settles back to 38lb. could this be tied to the p741 code?
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multiple posts on the same topic/problem is frowned upon -
it makes following and answering difficult -
 

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Super Moderator
2010 DTS
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87,572 Posts
Yeah That ^^^^^^^^^^
could this be tied to the p741 code?
No. I've had the P0741 code for years with my '03 and never had a problem. That said, I can't imaging any relationship between gear selection and fuel pressure.
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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71,095 Posts
Duplicate threads on the same subject have been merged.

P 0741 is the TCC (Torque Converter Clutch) failure code. Repair/permanent code clear requires complete transmission and torque converter removal and overhaul. $5300.

P 1860 is the TCC solenoid/circuit failure code.

Correct fuel pressure spec is 41 - 47 psi. Neither gear selection nor pointing downhill should not affect fuel pressure.

MAYBE there's a fault in the IMS (Internal Mode Switch - shift signals) inside the transmission (# 942). But that should set some sort of P code also.

4T80E solenoids and sensors.gif


Scroll through the P codes and see how many hundred P codes apply to fuel system faults. Of course, not all are possible in our 2000 - 2004 Sevilles, but the number of monitored faults is staggering.

 

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2001 SLS
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10 Posts
Discussion Starter #12
No p codes. Plenty of b codes. Tonight I tried to start the caddy and had no voltage to fuel pump. Ran the shifter thru the gears and fuel pump came on.
Is there anything in the transmission that would cause the fuel pump to not come on? I have a good scantool but not sure what to watch for.
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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71,095 Posts
Possibly the IMS - it sends the shifter P, N, and gear signals to the PCM.

What codes - and their definitions - did you see ? Any diagnostics are a help.
 

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2001 SLS
Joined
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10 Posts
Discussion Starter #14
Possibly the IMS - it sends the shifter P, N, and gear signals to the PCM.

What codes - and their definitions - did you see ? Any diagnostics are a help.
Last list of codes were after trying to start with low battery. Ddm B codes 1581 1591 1611 1621 3832 3833 ipm b code 1343. 2 p codes p410 and p 1189. I had some friends stop by and we noticed my motor mounts are letting the motor move more than it should. I don't feel its pulling on wires to kill voltage to pump wondering if the motor movement could cause something to shut down the pump. I have to turn the key off then back on to get fuel pressure. If that doesn't work I can shift gears and turn the key off then on to get pressure back. Sometimes it will die going down the road at hwy speeds. I have to shift to neutral turn the key off then on to get pressure then start the motor and back to drive. Kind of nearing in traffic. I have a parts car so I changed the pump. Does the same so there both good or both bad. I still at a loss as to what to do. I'm going to replace my battery today. Tired of pulling the back seat to hook up the jump box. My battery has no reserve. Been run down to many times. Alternator checks good. Maybe the oil pressure code??
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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71,095 Posts
Codes are worthless without definitions - we don't have all 4,000 or so memorized yet. Post #11, last line.
 

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2001 SLS
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10 Posts
Discussion Starter #16
The p1189 I have been reading as low oil pressure switch malfunction but theres Another definition I haven't seen till now. Fuel control bank2 sensor 1 I need to check into this.
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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71,095 Posts
Bank 1 (right bank, 1-3-5-7) is the firewall side.
Bank 2 (left bank, 2-4-6-8) is the front side

B2S1 is the left (front) bank O2 sensor - in the exhaust manifold collector.

Front O2 sensor B2 S1.gif
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
Joined
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20,253 Posts

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Super Moderator
2010 DTS
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87,572 Posts
I thought that was part of the reason for OBDII. Universal codes and definitions across the board for all manufacturers.
 
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