Volvo Owners Club Forum - View Single Post - Engine: S60: - Hesitation when accelerating, only when first starting the c

Virtus36 · Jun 1st, 2020, 19:16

Hi, I have a problem with acceleration (2004 S60 2.5T). When the car is first started, regardless of whether the engine is hot or cold, I get this stuttering hesitation.

I can get rid of it by accelerating at full throttle for a few seconds, eventually bringing back full power. It's strange, it almost feels like it unblocks something. The problem will then not come back until I switch off the engine and start it again. Even if I only switch off for a few seconds, it happens again every time.

My car has the plastic 'saddle' tank but does not have a PEM. Also does not have a pressure sensor on the fuel rail. I have replaced the fuel filter but the problem persists. Also cleaned ETM.

I am getting the dtc code P1234 (fuel pump driver module off line). As I said, I don't have a PEM on this car so I assume this is all handled by the ECM.

I would be very grateful if anyone has any ideas.

Thanks.

Jun 1st, 2020, 19:16	#1
Virtus36 New Member Last Online: Oct 16th, 2020 13:24 Join Date: Jun 2020 Location: York	Hesitation when accelerating, only when first starting the c Hi, I have a problem with acceleration (2004 S60 2.5T). When the car is first started, regardless of whether the engine is hot or cold, I get this stuttering hesitation. I can get rid of it by accelerating at full throttle for a few seconds, eventually bringing back full power. It's strange, it almost feels like it unblocks something. The problem will then not come back until I switch off the engine and start it again. Even if I only switch off for a few seconds, it happens again every time. My car has the plastic 'saddle' tank but does not have a PEM. Also does not have a pressure sensor on the fuel rail. I have replaced the fuel filter but the problem persists. Also cleaned ETM. I am getting the dtc code P1234 (fuel pump driver module off line). As I said, I don't have a PEM on this car so I assume this is all handled by the ECM. I would be very grateful if anyone has any ideas. Thanks.