Fuse F15 keeps blowing up

[Kazimierz]

Hi,
Citroen Xsara Picasso 2.0 HDi, 2003 (facelifted electronics version)

I have an issue with the F15 fuse in the BSM module (under the hood) blowing. The fuse doesn’t blow immediately but, for example, after two or three days. A blown fuse triggers errors for the EGR solenoid valves and the valve that disconnects the third piston of the high-pressure fuel pump. I found a wiring diagram which shows that elements are connected, but I'm not sure because those diagrams are propobly from pre_lift electronics version.

Currently, the vacuum lines for the EGR solenoids are blocked off by me. The computer shows the EGR position at 99%.
Online, there are similar threads about this specific fuse blowing, but concrete solutions are hard to find.

My theories:
The blocked EGR valve causes overload and a short circuit.
The short circuit occurs in one of the relays inside the BSM module.

What do you think could be causing the fuse to blow?

[GiveMeABreak]

It's possible if the EGR has been forcefully blocked or is jammed. The EGR has a self-clean function to help prevent sticking, so this could be an issue if it is being prevented from operating. Probably needs cleaning or replacing if it's stuck, given that the car is 22 years old.

If you want the wiring diagram, then provide the VIN here. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[Kazimierz]

Here is the VIN: VF7**************[VIN obfuscated, can be read by forum staff]
Accoring to EGR valve, it is old non-electronic one. It's operated through vacuum lines leading to electronic solenoid/valve thing. I'll appreciate for right wiring diagrams, thank you.

[GiveMeABreak]

e: Vacuum inlet (gas recycling regulation electrovalve).
f: Pneumatic control capsule for the EGR valve.
(5) Exhaust gas recycling valve (EGR).

The gas recycling valve is shut when it is not being pneumatically controlled (vacuum).

Operating phases when the control vacuum capsule is supplied with a vacuum:

• The gas recycling valve opens
• Part of the exhaust gas is absorbed by the engine (air inlet manifold)

The vacuum pump supplies the vacuum required for operating the following components:

• Exhaust gas recycling valve (EGR) (depending on the version)
• Pneumatic control capsule for the EGR valve
• Brake servo (depending on the version)

This may help:

Air circulation (as per arrows):
A: Air
B: Exhaust gas + Air
C: Exhaust gas

Note: The diagram relates to engines with a controlled turbo (injection ECU + electrovalve).

Reference	Designation	Part number in the electrical diagrams	Remarks
1	Injection ECU	1320	-
2	Recycling Regulation Electrovalve (EGR)	1253	-
3	Vacuum Pump	-	-
4	Turbocharging Pressure Regulation Solenoid Valve	1233	According to specification
5	Exhaust Gas Recycling Valve (EGR)	-	-
6	Air Inlet Manifold	-	-
7	Exhaust Gas Manifold	-	-
8	Boost Pressure Waste Gate	-	Vacuum-controlled
9	Pneumatic Control Capsule For The Waste Gate (On Turbocharger)	-	Vacuum-controlled
10	Catalytic Converter	-	-
11	Exhaust Turbine	-	-
12	Turbocharger	-	-
13	Air Inlet Turbine	-	-
14	Air Flow Meter + Air Temperature Sensor	1310	-
15	Air Cleaner	-	-
16	Inlet Manifold Pressure Sensor	1312	-
17	Air/Air Heat Exchanger	-	According to specification
18	Atmospheric Pressure Sensor (Integrated In The Injection ECU)	1320	-

I have the diagram for you, but you'll have to wait as we've moved to a new server and we are still fine tuning, so I don't have access at present, but will pop it up when I can.

[Kazimierz]

Ok, thanks.

[GiveMeABreak]

Here you are:



With the exception of the wiring codes, most of the component codes are indexed here:

PSA Electrical Diagrams - Wiring & Symbols Codes Index

[Kazimierz]

Thank you very much.

[Kazimierz]

My diagnostics aren't successful. It looks like no matter if I unpluged EGR solenoid and EGR throttle (diagram above lack of that conmponent) or CR pump 3rd pistion deactivator - fuse F15 keeps blowing. Some onlne threads lead to bad mass conector or losen cable, but non of them point specific element. Do you have a BSM pin out by any chance?

[Gibbo2286]

I would be looking for short circuits on the loom serving those items, tight turns and sharp corners biting into the wiring somewhere, especially as your fault is intermittent

[Hell Razor5543]

Just a thought (and possibly a silly one). You are fitting a fuse of the correct rating?

[Kazimierz]

Yes, I even try diffrent and still the same.