Technical [HELP] Multiple Fault Codes on Fiat Ducato 2.3 Multijet (2021) After Battery Drain & Jump Starts

[losttalisman]

(TLDR at the end)



Hi everyone,

I'm a new owner of a 2021 Fiat Ducato 2.3 Multijetwith relatively low mileage (~30,000 km). The vehicle was recently left with a completely drained battery, and several jump-start attempts were made to get it going again.



Since then, the Check Engine Light has come on, and the OBD scanner at the inspection showed the following fault codes:

• P0641 – The engine control system has detected a problem with the electrical circuit that supplies reference voltage (usually 5 volts) to one or more sensors. This circuit is labeled as "Sensor Reference Voltage A."
• P24D1 – The system has detected that the pressure sensor for the diesel particulate filter is not changing its signal as expected. The signal appears to be stuck or frozen.
• P0236 – The engine control unit has detected that the signal from the turbocharger boost pressure sensor is outside the expected range or behaving inconsistently.
• P0238 – The engine control unit has detected that the signal from the turbocharger boost pressure sensor is higher than the allowed or expected level.

The codes were cleared by the dealership, and for several days everything seemed fine — the Check Engine Light was gone, and the car was driving normally.



But now, the Check Engine Light has returned, and with it, the van’s behavior has changed again:

• Fuel consumption has gone up significantly
• The van feels like it’s not running as smoothly as before

What I’ve Checked So Far:

• Battery voltage looks good with a multimeter:
  • 12.9V, 12.4V, and 12.7V (engine off, different times)
• Battery seems to be holding charge fine now, but I suspect the previous full discharge and repeated jump-starting may have affected the electronics.
• Engine starts and runs, but the Check Engine Light remains.

My Diagnosis (So Far):

From what I’ve researched and tested, it looks like the root cause might be related to the issue in the 5V reference circuit (P0641), and that all other fault codes are the consequence.

1. Could these fault codes be caused by the battery being completely drained and the vehicle being jump-started multiple times?
2. Is it possible that something was damaged during the jump-start process, especially if the cables weren’t connected or grounded correctly?
3. Can a problem in the 5-volt reference circuit (P0641) cause multiple other sensors to fail or trigger related codes?
4. Has anyone seen these exact codes (P0641, P24D1, P0236, P0238) come up together before? If so, what was the cause?
5. Since the codes were cleared and the problem disappeared for a while, does that suggest anything specific?

I appreciate any kind of information.

Thank you!







TL;DR

2021 Fiat Ducato 2.3 Multijet showing multiple fault codes (P0641, P24D1, P0236, P0238) after a battery drain and jump starts. After clearing the codes, the Check Engine Light came back, and the van is now experiencing higher fuel consumption and rougher driving. Suspecting issues with the 5V reference circuit (P0641) affecting other sensors. Has anyone had similar issues or know if jump-starting could cause this? Appreciate any insights!

 

[Googlebot]

Firstly, I would check all fuses and make sure they are sound.

Secondly, a battery that has been fully drained is usually toast, I would change it for a known good or even better, a new one.

4 years is okay for a battery so don’t feel too bad.

Jump starting repeatedly can cause several issues with spikes in voltage, it may be you have knackered something but I would make sure the basics are covered first.

Fingers crossed it’s a bad battery and all will be well.

Also, check the earth straps to engine and gearbox, they are known to be poop.