2004 c5 hdi 110 cooling fan woes FIXED and now running (pg 6 on) .

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citroenxm
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

After checking all the bsi fuses. Lexia now cannot connect at all to the car..
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

I'm done for today.. I think I'll just have to pick up that ecu and bsi off ebay..
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by MGmike »

citroenxm wrote:
20 Jul 2021, 11:51
Its strange I cannot erase engine ecu faults..
Not really. Permanent faults need to be fixed before they will clear.
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

Not useually.. You can clear them but they come back. I've never had communication fault without it even trying whay happens is it attempts to clear faults but says faults remain..

Anyway.. I've made an offer on the ecu kit and bsi on ebay.. See what happens.. Get it swap it in.. Then see what next.. I'm convinced its the ecu at fault..
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Paul-R
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by Paul-R »

Do you read my post a couple of pages earlier about a similar problem I had with our old Xsara?
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

Yea I did. I had a go by keeping the lift pump running constantly as a pre check.. The engine still stalled leaving the pump running. So I'm Moee convinced the ecu has copped it
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Hell Razor5543
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by Hell Razor5543 »

I know I don't know much about the fuel system of these cars, but is it possible that (when the pump is primed and the engine is running) the natural action of the engine PULLS the fuel through without needing the lift pump to keep pumping? Isn't there a high pressure pump taking the fuel pressure to a much higher level?
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GiveMeABreak
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by GiveMeABreak »

Paul - as per you other post, I'll put up some info on this specific system as fitted to the MK I with your engine. It may help you work out when the fan is operating and when not and which system controls what:

So this C5 has a single 500W Fan with 3 speeds. Below are the normal operating conditions:

Three Speed Fan Unit
InfoData
1st gear97 °C or air conditioning in operation
2nd speed101 °c or 17 bar in the cooling circuit
3rd speed105 °C or air conditioning in operation
Air conditioning cut-off115 °c or 30 bar in the cooling circuit
Warning118 °C
Post-cooling6 minutes
Temperature sensorTemperature: Diesel injection , Warning , heating/ventilation

Components
Paul Cooling A.PNG
Paul Cooling A.PNG (35.37 KiB) Viewed 33 times
Key:
Ignition+: + ignition on
+ BAT: Battery +
BSIBuilt-in systems interface
1320Engine ECU
1304Injection double relay (engine relay unit)
1508Slow speed control relay
1509Fast speed control relay
1510electric cooling fan unit
1514Mid speed control relay

Calculating the fan unit speed
The engine ECU sets the fan unit speed instruction depending on the following parameters:
  • Engine coolant temperature measured by the sensor
  • Cooling requirement linked to air conditioning, controlled by the B.R.A.C
Checking the fan unit speed

The fan unit is fitted with 3 functioning speeds:
  • The engine ECU controls the slow speed and the fast speed
  • The BSI controls the mid speed, depending on the information delivered by the engine ECU via the CAN network (engine coolant and air con circuit pressure temperature)
  • Slow speed is obtained by supplying the cooling fan via a resistor arranged in series in the supply circuit.
  • Mid speed is obtained by supplying the fan unit via two resistors wired in parallel on the supply circuit.
  • Fast speed is obtained by supplying the cooling fan directly.
The 2 resistors are located on the front dash, near the air-air exchanger and the fan unit.

Post ventilation
When stopping the engine, the engine ECU controls the post cooling (slow speed), if the measured engine coolant temperature is over a programmed level.

The fan unit cannot be started in the following cases:
  • Operation in power latch (*)
  • Switching off of the engine ECU electronics
  • Engine starting phase
(*) Mode in which the equipment remains supplied for a period after the ignition is switched off.

A fault concerning the fan unit (or the slow and fast speed controls) leads it to work in fast speed.
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

Lexia couldn't run the fan in slow speed in actuator tests.. I also could not make lexia clear faults.. It always tries to but can say faults remain. All I got was no communication possible..
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

Hell Razor5543 wrote:
20 Jul 2021, 20:36
I know I don't know much about the fuel system of these cars, but is it possible that (when the pump is primed and the engine is running) the natural action of the engine PULLS the fuel through without needing the lift pump to keep pumping? Isn't there a high pressure pump taking the fuel pressure to a much higher level?
The engine pump is NOT a pump.. Its a fuel rail pressureiser.. It needs a feed of fuel from the lift pump as its not a pump in itself..
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GiveMeABreak
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by GiveMeABreak »

citroenxm wrote:
20 Jul 2021, 20:40
Lexia couldn't run the fan in slow speed in actuator tests.. I also could not make lexia clear faults.. It always tries to but can say faults remain. All I got was no communication possible..
Was the engine running when you tried the tests? If not try that.
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Hell Razor5543
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by Hell Razor5543 »

Erm, the engine won't run!
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

[quote="
Marc..

It ran the fast speed without the engine running.. Then slow speed it just clicked clicked..

As James says.. It won't run.. It starts after its first prime then stalls.. 20 seconds running only.
Last edited by citroenxm on 20 Jul 2021, 20:58, edited 1 time in total.
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GiveMeABreak
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by GiveMeABreak »

I'm just coming in on the end of this at Paul's request - I wasn't aware it was a non-runner but now I know, that would make sense given the info I posted - the engine ECU controls the slow and fast speeds and the BSI the Mid speed - they all need to be running for the system to work as far as I can see... which may explain why you are getting the fan running with a direct feed, but not via the car as the other components are not running.
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Re: 2004 c5 hdi 110 cooling fan woes and now not running....

Post by citroenxm »

GiveMeABreak wrote:
20 Jul 2021, 20:57
I'm just coming in on the end of this at Paul's request - I wasn't aware it was a non-runner but now I know, that would make sense given the info I posted - the engine ECU controls the slow and fast speeds and the BSI the Mid speed - they all need to be running for the system to work as far as I can see... which may explain why you are getting the fan running with a direct feed, but not via the car as the other components are not running.
Yes of course Mrac. I appriciate your input. I think the engine ecu is dead. I've tried another bsm and I get same results..

I'll get that 40 quid ecu and bsi with key off ebay and see what happens..