Volvo v70 2005 t5 fuel problem

[Alfiehiron]

I have a Volvo v70 T5 2005

It has some sort of fueling problem.

After about 20 mins of driving it will start to lose fuel pressure and lose throttle. Once I turn the engine off for 10 seconds and start up it’s okay for another 20 mins (this only really by happens on less than 1/4 tank)

Sometimes it will do the same thing at around 3k+ revs.

I’ve changed the fuel pump, fuel pressure sensor, pump control module and fuel filter.

I went and got it scanned and it come back with these codes (ignore top one)

Thank you

[lrock]

i had the 1/4 tank shutoff/stall issue in my 2001, in my case it was the fuel sender on the side opposite the fuel pump side needed replaced. that or keep it over a 1/4 tank. ymmv. after it cut out on me on the highway for the 3rd time and i needed a tow i replaced the fuel sender.

for the last code, here's the procedure
TL/DR: ignition on, check for an open to the level sensor on the pump side, check for a short to supply voltage on the sensor on the pump side.

Code:
CEM-4A37
Definition:
Fuel Level Sensor. Short-Circuit To Supply Voltage Or Open-Circuit
Description:
The central electronic module (CEM) continuously checks the signal from the sensor on the pump side which indicates the level in one of the fuel tanks. The diagnostic trouble code (DTC) is stored if the central electronic module (CEM) registers an open-circuit in the connection to the sensor on the pump side in the tank or a short-circuit to supply voltage in the sensor. The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.
Cause:
Open-circuit in the connection to the fuel level sensor on the pump side.
Short-circuit to supply voltage in the sensor on the pump side.

here's the second code Make:
Volvo
Code:
CEM-3F90
Definition:
Fuel Pump Relay. Open-Circuit Or Short-Circuit To Ground
Description:
Central electronic module (CEM) checks the fuel pump relay, and activates it, when an approved check has been made by the system for Immobilizer. The fuel pump relay is located internally in the Central electronic module (CEM). The fuel pump relay sends voltage feed to the fuel pump when the relay is activated. If Central electronic module (CEM) detects that the voltage on the output to the fuel pump is too low, the diagnostic trouble code is generated. The diagnostic trouble code (DTC) can be diagnosed when the fuel pump is activated. Note! When troubleshooting, the fuel pump may not be supplied with voltage by an external power source without first disconnecting the connector to the Central electronic module (CEM). If the connector is not loosened and the fuel pump is supplied with voltage, this can lead to failure of an internal ground conductor in the Central electronic module (CEM). In turn, this can lead to a number of other malfunctions in the vehicle and that Central electronic module (CEM) must be replaced. The following applies to vehicles with fuel pump module (PEM): Central electronic module (CEM) checks the voltage feed to the fuel pump module. The Central electronic module (CEM) activates the voltage supply to the fuel pump control module after the checks carried out by the function for the immobilizer have been approved. If Central electronic module (CEM) detects that the voltage on the output to the fuel pump module (PEM) is too low, the diagnostic trouble code is generated. The diagnostic trouble code (DTC) can be diagnosed when the fuel pump is activated.
Cause:
Damaged power supply fuse.
Open circuit on cables for voltage feed between fuse box engine compartment and Central electronic module (CEM).
The cable for voltage feed between Central electronic module (CEM) and fuel pump module (PEM)/fuel pump is short-circuited to ground.


here's your wiring diagram

https://vidaresources.volvocars.biz/ewd ... 77202.html

[DavidE7]

Swap the fuel pump relay to another position. Check for fuel pressure at schraeder valve and then tape the fuel pressure gauge to the windshield so you can monitor it for changes while driving. Intermittent problems unfortunately end up being wiring harness problems with a fraying wire or electrical connector that in't making good contact due to contamination or reduced contact force.