No DTCs displayed, but……

[Pete_D60]

Hi All,
I recently acquired a 2014 C3 Picasso with a few issues.
There are no DTCs coming up on the dashboard, but my ArtiDiag800BT has picked up P0693, P0691, P0495, P0494, P0493 as per the attached report.

DTC Report

All looks to be associated with the fan control side of things and I’ve replaced the 1529 fan resistor unit which was badly corroded and the varistor open circuit. However, after clearing the codes, they reappear.
So, more work to do, but looking at the codes, I’m thinking it looks like a status condition issue with the actual status not getting back to the ECU.

Do you guys agree or am I barking up the wrong tree?

Thanks in advance,

Pete

[GiveMeABreak]

Pop the VIN up Pete and I'll take a look. 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.

[Pete_D60]

Hi Marc,

The VIN is VF7**************[VIN obfuscated, can be read by forum staff]

Thanks & regards,

Pete

[GiveMeABreak]

Fault Code:	P0693
Description of Fault:	Electric cooling fan unit: Short circuit to earth on the fan assembly control 2 Description of the diagnostics: Electrical fault detected for 200 ms
Conditions for Fault to clear:	Engine running hot for 5 minutes with the cooling fan activated
Downgrade Modes whilst Fault is active:	Inhibiting of the exhaust heat recovery function. 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 No automatic stopping of the internal combustion engine
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Ditto the above for P0691 but refers to: Electric cooling fan unit: Short-circuit to earth or open circuit on the control of cooling fan 1.

Fault Code:	P0495
Description of Fault:	Electric cooling fan unit: Twin speed: Incoherence between the reference value (high speed) and the status of the fan assembly; Variable Speed: Short-circuit to earth or to the battery or open circuit on the status of the cooling fan' Description of the diagnostics: Incoherence between the reference value (high speed) and the status of the fan assembly (For 5 seconds)
Conditions for Fault to clear:	Activation of the cooling fans unit
Downgrade Modes whilst Fault is active:	Inhibiting of the exhaust heat recovery function 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 No automatic stopping of the internal combustion engine
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Fault Code:	P0494
Description of Fault:	Electric cooling fan unit: Twin speed: Incoherence between the reference value (low speed) and the status of the fan assembly. Description of the diagnostics: Incoherence between the reference value (low speed) and the status of the fan assembly (For 5 seconds).
Conditions for Fault to clear:	Activation of the cooling fans unit
Downgrade Modes whilst Fault is active:	-
Symptoms:	Engine overheating with illumination of the engine coolant temperature indicator light No automatic stopping of the internal combustion engine
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Similar for P0493:

Electric cooling fan unit: Twin speed: Incoherence between the reference value (no control) and the status of the fan assembly

[Pete_D60]

Thanks Marc,

So, from that I think the next thing to check is continuity of the elements in the fan control circuits. Do you have a schematic of the interconnections available or can you link to it on the forum please?

Once that’s completed and if all okay, I guess the fan unit itself is the likely culprit?

Thanks,

Pete

[GiveMeABreak]

Your best bet is to just replace the whole assembly to be honest. I don't have the circuit diagram concerned, sorry.

[Pete_D60]

Sounds like an expensive option Marc, particularly if it turns out to be a wiring continuity issue.

I’ll try and find something online and if successful, I’ll post it on the forum.

Thanks,

Pete

[Pete_D60]

UPDATE:

After disconnecting connectors from the fan and fan resistor relay unit, ECU, I couldn’t see anything obvious like a corroded pin or loose wire etc.
As I had to go out, I reassembled everything and out of idle curiosity ran a diag with my ArtiDiag800BT, fully expecting the DTCs to reappear after I cleared them.
However, whatever I disturbed seems to have done the trick and everything is working as it should - DTCs cleared!

[508c5]

Fault Code:	P0693
Description of Fault:	Electric cooling fan unit: Short circuit to earth on the fan assembly control 2 Description of the diagnostics: Electrical fault detected for 200 ms
Conditions for Fault to clear:	Engine running hot for 5 minutes with the cooling fan activated
Downgrade Modes whilst Fault is active:	Inhibiting of the exhaust heat recovery function. 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 No automatic stopping of the internal combustion engine
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Ditto the above for P0691 but refers to: Electric cooling fan unit: Short-circuit to earth or open circuit on the control of cooling fan 1.

Fault Code:	P0495
Description of Fault:	Electric cooling fan unit: Twin speed: Incoherence between the reference value (high speed) and the status of the fan assembly; Variable Speed: Short-circuit to earth or to the battery or open circuit on the status of the cooling fan' Description of the diagnostics: Incoherence between the reference value (high speed) and the status of the fan assembly (For 5 seconds)
Conditions for Fault to clear:	Activation of the cooling fans unit
Downgrade Modes whilst Fault is active:	Inhibiting of the exhaust heat recovery function 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 No automatic stopping of the internal combustion engine
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Fault Code:	P0494
Description of Fault:	Electric cooling fan unit: Twin speed: Incoherence between the reference value (low speed) and the status of the fan assembly. Description of the diagnostics: Incoherence between the reference value (low speed) and the status of the fan assembly (For 5 seconds).
Conditions for Fault to clear:	Activation of the cooling fans unit
Downgrade Modes whilst Fault is active:	-
Symptoms:	Engine overheating with illumination of the engine coolant temperature indicator light No automatic stopping of the internal combustion engine
Suspect Areas:	Fan assembly Fuse Electrical harnesses Connectors

Similar for P0493:

Electric cooling fan unit: Twin speed: Incoherence between the reference value (no control) and the status of the fan assembly

Hello,

what are the chances of an overheating in case of a P0495 POP UP IN A SCAN but no light appears on the dash ?

thx

[GiveMeABreak]

Lights on the dash are limited to certain conditions - like overheating, battery not charging, low oil pressure, emissions faults. They generally won't light up for every type of fault, unless it risks engine harm / or a serious problem.

So you may have a fault in a piece of equipment like an engine fan control unit or relay that may for example prevent the fan from operating - this may not be an issue and probably won't put a warning light up until the actual engine temperature rises to a high level that will trigger an overheating warning. That's when you'd use a diagnostic to help pinpoint the cause.