2006 S60 2.5 T5 fuel electronic module

Robert Carter · Post by **Robert Carter** » 28 May 2017, 11:20

I have recently replaced the fuel pump on my s60 and it won't pump gas from the driver's side of the tank, I have removed the pump and rerouted the hosing to make sure there is no kinks in the hose, I have replaced the driver's side sending unit and now the gas gauge seems to be working although it reads 1/2 tank most of the time when I know there is less gas in the tank. When I drive say more than 30 miles or so the gas gauge will drop to empty, if I stop the car for a while then start it again the gauge will work again. Yesterday I drove on a longer trip and the car actually stop running and the gas gauge had been on empty for a while. I set for about 10 minutes and then the car started right up. when I arrived home the PEM was hot

I guess the questions I have for everyone here is.

1. Can a bad PEM cause the car to stall?
2. Does the PEM have anything to do with the pump not pumping from the driver's side of the tank?
3. the fuse that operates the back doors,trunk and probably some others thing can that fuse be blown because of the PEM?

A few weeks ago when I was installing the pump and was running the car for a while the pem was scalding hot, does that mean anything?

I really appreciate any help. Thanks Robert.

Post by **precopster** » 28 May 2017, 15:25

Simple check is to check for voltage going to the pump terminals. It's a 12V feed and if yours is the type with the connector at the top of the pump it's dead easy to use a piercing probe on the 12V and chassis wires.

Robert Carter · Post by **Robert Carter** » 31 May 2017, 20:36

The pump works it just doesn't pump from the driver's side of the saddle type tank. this tank can be completely empty on one side and full on the other side. Put a new sending unit on and the gas gauge worked for about two weeks and now it doesn't work any more. I'm thinking it's the PEM any other thoughts? Thanks Robert.

Post by **mrbrian200** » 31 May 2017, 22:22

Robert Carter wrote: ↑31 May 2017, 20:36 Put a new sending unit on and the gas gauge worked for about two weeks and now it doesn't work any more. I'm thinking it's the PEM any other thoughts? Thanks Robert.

The level sensors don't loop through the PEM, their wires run through the harness directly to the CEM.
I would probably be looking for terminal corrosion or a break in the electrical connections/ ground point(s).
The PEM was originally located under the car near the fuel tank, on most of them the PEM was relocated into the trunk while still under warranty. Because of this the wiring looms back there probably look a little complicated/crazy. There's a sub harness which was added to extend the electrical connections to the relocated PEM. I would start by looking at those connectors/connections for corrosion or loss of continuity. The ground point for the pumps and PEM is ring terminal under the rear seat cushion inside the passenger compartment, passenger side.
All of it runs through connector 54/36, connector at the fuel tank looks like:

Post by **precopster** » 31 May 2017, 23:28

Pump only pumps fuel from the right side of the car (I'll avoid using driver or passenger side terminology for the sake of correctness). The return line going to the left side is merely a loop and has no open ends for intake of fuel.

Sensors are on both sides so that CEM can work out an average of both left and right readings. Fuel will slosh around to either side depending on road camber.

Post by **mrbrian200** » 01 Jun 2017, 01:54

Schematic shows two pumps at least on some 5cyl turbo variants, I'm a little confused: I am assuming AWD with the saddle shaped tank would have both. Schem tries to be clear, all turbo variants, but I think I've seen people say that the NON AWD cars don't use the second pump (hump in the middle is shallower and fuel does slosh from side to side). But don't quote me. One is identified as 'fuel pump' 6/33, the other is 'feed pump' 6/31. I'm looking at TP 3988202 (2006 S60) page 45.
Anyway- he says he has two pumps. He's has issues with two things back there - one (the feed pump) is controlled by the PEM, but the level sensors do not go through the PEM. So I'm thinking if the problems are related it would have to be in the wiring loom. A good guess being water/road salt intrusion past a weather pack seal into a connector which the wires for both malfunctioning items run through (54/36, or maybe the supplemental harness added to relocate the PEM depending how they wired that and if that service was performed on this particular vehicle)

Robert Carter · Post by **Robert Carter** » 01 Jun 2017, 13:26

My car has the saddle tank and I can't get it to pump from the driver's side tank.

Post by **mrbrian200** » 01 Jun 2017, 14:43

Unplug the connector from the PEM and touch battery positive to pin2 on the harness connector (Blue wire) and see if it runs. The feed pump you're testing grounds directly to the chassis which means it runs on DC voltage on some sort of duty cycle governed by the PEM. I'm not sure the PEM would not turn on this pump if it thinks the LH side is empty. Check for open or short across pins 2 & 3 for the LH level sensor at connector 54/36 going to the tank (wire colors should be Brown and Green)

The main fuel pump (which is working or the car wouldn't run) grounds back through the PEM but is controlled variable speed/PWM may not have a true ground path with vari-speed control circuitry in play.

Post by **mrbrian200** » 01 Jun 2017, 15:01

What I'm not sure about is how the PEM communicates with the ECU to know what the level sensors are indicating. The PEM may not know thus duty cycling the feed pump all the time. The schem doesn't tag that line (pin 1 at the PEM from the ECU) as either can or lin data, so I'm thinking it's a one way communication Pulse width modulation signal the PEM simply reads/receives strictly regulating fuel pressure/volume. I know replacing a PEM is plug and play/not programmed to the vehicle.

Robert Carter · Post by **Robert Carter** » 02 Jun 2017, 19:46

mrbrian200 wrote: ↑01 Jun 2017, 15:01 What I'm not sure about is how the PEM communicates with the ECU to know what the level sensors are indicating. The PEM may not know thus duty cycling the feed pump all the time. The schem doesn't tag that line (pin 1 at the PEM from the ECU) as either can or lin data, so I'm thinking it's a one way communication Pulse width modulation signal the PEM simply reads/receives strictly regulating fuel pressure/volume. I know replacing a PEM is plug and play/not programmed to the vehicle.

Not programed to the vehicle does that mean that if I need a new pem it doesn't have to be programed? I can just plug it in?

I have another question
on the not pumping from the driver's side of the tank, can I just run a t joint off the pump side of the tank and run a flexible fuel resistant hose over the hump and attach it to the yellow suction piece that attaches to the bottom of the sending unit? I am tired of trying to keep the hose from kinking.