Help with codes P0693 and P0691

[MyC3]

Hi, My 1.6hdi Citroen C3 2012 model is returning the error codes P0693 and P0691 . As a result of this it would appear that the car is in idle mode, will not do more than 3000 RPM and is low on power.
There was a fault with the Radiator fan controller/relay unit 1529. I changed the unit, it was obviously broken as the spiral resistor was corroded and loose.
I want to also say that I thought the fan motor might be the cause of the error codes. So I have tried connecting a brand new fan motor to the 1529 unit .
The error codes still appear.
The tester I used reports the following messages
P0691 "Electric fan unit cooling fan control 1 circuit open/short to ground"
P0693 "Electric fan unit cooling fan control 2 circuit short to ground"

The code P0493 also appeared a few days ago but is not present now.

There is another error code which may or may not be related that appears.
U1218 " Inter-systems Can. One of the parameters present in a live data transmitted by the BIS is invalid"

There has been an intermittent error code too P 11B2 and P14A4 which has reference to the EGR circuit.

I am running short of time now as the MOT is due. Any help on getting the car out of the idle state would be deeply appreciated.
VIN VF7**************[VIN obfuscated, can be read by forum staff]

[MyC3]

I am wondering if the problem I have observed could be due to an error in the motor ECU.
The problem relates to error codes P0691 and P0693.
I have replaced both the relay unit (1529) and the Radiator cooling fan (1553) but still have the error codes appearing.
Should it normally be enough to just clear these fault codes on the tester to remove them? If so then why can the fault still be present as I have tried to delete the codes several times but they keep reappearing when the ignition is on.
If the error is possibly due to the ECU , then how can I confirm this? Can I measure the voltages on the pins on plug 2VNR for example when the ignition is on and if so what voltages would I expect to see with a cold engine?

The car is a C3 1.6hdi 2012.
Vin code was posted on my previous post sent 2.2.2022
Lots of 2s in that date

[MyC3]

I have been informed that these two relays can be the cause of a problem with the engine performance . My engine will not rev above 3000RPM and has very little power.
I have a photo of these two relays . It is I understand , of the peugeot 206 . They are also on the C3 I imagine.
The question is . What are these two relays function ?
Where are they situated on the Citroen C3?

The car is presenting the error code P0691 and P0693.
This is a cross model question as it is both 206 and C3 related.

[Huskyxantia]

Rad fan resitor relays ? Control fan speed Looks about that area

[GiveMeABreak]

I have merged your 2 topics and deleted a third on the same issue!, please don't do this as it causes duplication of answers. You won't get answers any quicker. People need time to get around to reading the hundreds of posts a day we get here.

Here are you Fault Code descriptions:

Fault Code:	U1218
Description of Fault:	Intersystems CAN: One of the parameters present in a datastream sent by the BSI is invalid. Faults in communication between ECUs on the CAN network.
Conditions for Fault to clear:	Driving for 5 minutes
Downgrade Modes whilst Fault is active:	Reversible deactivation of the vehicle speed limiter, Reversible deactivation of the vehicle cruise control, Request to stop the air conditioning, Deactivation of the air conditioning.
Symptoms:	Jerking/stalling, Starting problem, Lack of power
Suspect Areas:	Engine ECU [*]Intersystem CAN network[/list]

Fault Code:	P0493
Description of Fault:	Speed fan assembly: Incoherence between the reference value (no control) and the status of the fan assembly. Electrical fault detected for 5 s
Conditions for Fault to clear:	Driving for 5 minutes from a cold engine, until the coolant temperature reaches 90°C
Downgrade Modes whilst Fault is active:	Lighting of the coolant temperature warning lamp Prohibiting of regeneration of the particle emission filter and stopping of the requests in progress Deactivation of the particle filter regeneration forced by the diagnostic tool
Symptoms:	Engine overheating with illumination of the engine coolant temperature indicator light
Suspect Areas:	Fan assembly, Fuse, Electrical harnesses, Connectors

Fault Code:	P0691
Description of Fault:	Electric cooling fan unit : Short-circuit to earth or open circuit on the control of cooling fan 1. Electrical fault detected for 5s.
Conditions for Fault to clear:	Engine running hot for 5 minutes with the cooling fan activated.
Downgrade Modes whilst Fault is active:	Lighting of the engine coolant temperature warning lamp Prohibiting of regeneration of the particle emission filter and stopping of the requests in progress Deactivation of the request for regeneration of the particle filter from the diagnostic tool
Symptoms:	Engine overheating with illumination of the engine coolant temperature indicator light
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Fault Code:	P0693
Description of Fault:	Electric cooling fan unit: Short circuit to earth on the fan assembly control 2. Electrical fault detected for 5s.
Conditions for Fault to clear:	Engine running hot for 5 minutes with the cooling fan activated
Downgrade Modes whilst Fault is active:	Deactivation of the request for regeneration of the particle filter from the diagnostic tool
Symptoms:	Engine overheating with illumination of the engine coolant temperature indicator light
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Here is the diagram showing the cooling fan Control units - a 2 pin Green and 4 pin green (or black connector):

2 Pin Green (2VGR
1587 : left fan assembly supply
1589 : Fan unit module power supply

4 Pin Green (or Black) 4VGR or 4VNR
1540G : fan control 1 (-)
1550G : fan control 2 (-)
1590 : Fan unit relay power supply
1599G : Fan unit diagnostic info





Location

[MyC3]

I have posted these extra posts because the information concerning these two relays is completely new information I have received. I was not aware of it in the original posts. I dont know if people read through old posts again. If not then it doesnt help users that people just see the old tiltle. I am trying to continue the fault finding by following the thread related now to these two relays. I have not been able to find other problems and have changed the 1529 unit with the big spiral resistor used to reduce the fan motor speed.
The citroen dealer service dept said the fault must be the fan itself ,based on the fact that I had changed he 1529. But there diagnosis wasnt correct. I tried a new fan motor just to be sure. It didnt help at all. So, back to these 2 relays

[GiveMeABreak]

I've now added your P0493 and U1218 faults in too. This is the one that is likely causing your reduced power mode. A communication issue between the Engine ECU and the BSI. So check that you have not disturbed any wiring blocks / connectors whilst undertaking previous work.

Neither of the EGR fault codes ( P11B2: Measurement of the position of the EGR exchanger by-pass: Short circuit to positive & P14A4: EGR exchanger bypass: Confirmed jammed shut (cold side)) indicate a reduced power mode, but obviously these need addressing too.

[aerodynamica]

I'm not sure myself but I found this similar one on this C3 forum: https://citroenc3owners.com/questions-a ... t4008.html

And the recommendation was that it is the fan unit. If you've already replaced it though it's worth checking the plugs are clean after being disturbed.

[MyC3]

Thanks.