C5 Petrol - Engine Starting Wiring Issue

[femtiolappen]

It's a good point, but the hair dryer in and around the engine bay wiring would seem to indicate the fault is there I suspect

Yes , inside car it will not help. The main cablage in engine bay it is , sometime when not so cold I can only by puting my hand on it make the engine lamp shine inside the car. Magic

[GiveMeABreak]

This is the wiring for the Magneti Marelli (EW10J4 Petrol Engine) as per your Specs:

(I've also changed the title of the thread as we know it doesn't have a CPH and it could be misleading)

If you could localise where you are applying the heat and eliminate the areas that do not have an effect using the diagram below, maybe you can identify the likely location / harness / connector giving the problem.

I would certainly check out the pins on the connectors to see if any are loose or shorter than the others too.

There should be 3 main connectors on the engine ECU, identified in the diagram along the sides of [1320]

• 32V NR (32 Pin Black)
  [*[48V MR (48 Pin Brown)
• 32V GR (32 Pin Grey)

Code	Component / Wire
1320	Engine ECU
BM34	Engine Slave Unit 34 Fuse(S)
1313	Engine Speed Sensor
1253	All Or Nothing Solenoid Valve (EGR)
1350	Upstream Oxygen Sensor
1351	Downstream Oxygen Sensor
1270	Carburettor Or Throttle Housing Heater Resistor
1334	No. 4 Cylinder Injector
1333	No. 3 Cylinder Injector
1332	No. 2 Cylinder Injector
1331	No. 1 Cylinder Injector
1312	Inlet Air Pressure Sensor
1115	Cylinder / Reference Sensor
1215	Canister Discharge Electrovalve
1240	Induction Air Temperature Sensor
1135	Ignition Coil
1220	Engine Coolant Temperature Sensor
1120	Knock Sensor
1211	Fuel Gauge Pump
7306	Cruise Control Safety Switch (Clutch)
7113	Power Steering Stop Sensor
1262	Motorised Throttle
1261	Accelerator Pedal Position Sensor
C001	Agnostic Connector
0004	Instrument Panel
BSI1	Built-In Systems Interface
CA00	Ignition Switch /

[Paul-R]

Can you take a photograph to show exactly where you point the hairdryer in the engine bay?

[femtiolappen]

Can you take a photograph to show exactly where you point the hairdryer in the engine bay?

Ok I will do

[femtiolappen]

Main cablage , it take 2min its 9c outside

[femtiolappen]

Step 2 and 3

[Hell Razor5543]

That suggests a poor electrical contact of some kind (such as a cracked solder join). I have seen some solder joins with a hairline crack that will (at a low enough temperature) open up far enough to cause that circuit to fail.

I would also (after correctly disconnecting the batter) find any connectors in that area, unplug them individually, spray some proper contact clear in, and then plug/unplug them a couple of times (helps to clear and dirt/tarnish). Once you have finished with one connector (and it is plugged back in), move onto the next connector, and repeat (until all connectors have been cleaned up).

[Paul-R]

We could do with a diagram showing where the wiring harness has solder joints and connectors. Is this something you can dig up Marc?

[GiveMeABreak]

The connectors are shown in the wiring diagram as you can see, and will then either route directly to, or via an Interconnection Harness to the relevant components / sensors / ECUs. The only soldering I can see would be integral to the engine fuse box or the BSI - or internal to the ECU, for which we don't have circuit diagrams for I'm afraid Paul.

[femtiolappen]

I Have seen a lot of solder join already in the main cablage , So far they look ok! Citroën check all cablage with no problems , but the car was indoors so it was 20-24c

[GiveMeABreak]

Yes, of course where the cables join the interconnection harness - but those should be easy to check if they are visible.