engine management light comes on with code P1668

Questions specifically about a Diesel powered C3 (usually engine or fuel related problems)
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Diesel engine related problems
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My Name: rickyc1977

Member
Posts: 5
Joined: Thu Feb 18, 2016 6:17 pm
Model: C3 2002-2005, Original shape model
Year: 2004 (54)
Engine Size: 1.4 (8v)
Fuel Type: Diesel
Mileage: 100000
Trim Level: Desire
Gearbox: Manual 5 speed
DPF: Yes
LHD or RHD: RHD (UK)

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1.4 hdi engine management light keeps coming on.

I have had a code reader on it and it comes up with a code p1668 and when i have research it on line it is PCM-IDM Communications error an that is as far as i can find out.

So my Question is does any body know what could be causing this fault and what can i do to fix it ?

i have re-set the error more than once but it will keep coming back till the problem is fixed
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My Name: Arfur Dent

Guru
Posts: 3520
Joined: Sat Jul 23, 2011 3:47 pm
Model: C3 2002-2005, Original shape model
Year: 2002 (52)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 100000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
Has thanked: 345 times
Been thanked: 135 times

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rickyc1977 wrote:1.4 hdi engine management light keeps coming on.

I have had a code reader on it and it comes up with a code p1668 and when i have research it on line it is PCM-IDM Communications error an that is as far as i can find out.

So my Question is does any body know what could be causing this fault and what can i do to fix it ?

i have re-set the error more than once but it will keep coming back till the problem is fixed
Hi rickyc1977

p1668 and when i have research it on line it is PCM-IDM Communications error - which is an error in communications between the Powertrain Control Module and the Injector Drive Module. Both modules are part of the Engine ECU. They can't be separated.

So, its either an internal fault with the Engine ECU, but more likely a problem with an injector or injector loom that is affecting the modules in the ECU.

Does the car run the same as it did before the fault appeared?


Your generic reader is just that, a generic reader. If you wanted more information and, as possible for some faults, so diagnostic tips the tool to use is The Lexia tool for Citroen (from ebay) or Amazon (click here). There is a topic covering just lexia here (click).
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My Name: rickyc1977

Member
Posts: 5
Joined: Thu Feb 18, 2016 6:17 pm
Model: C3 2002-2005, Original shape model
Year: 2004 (54)
Engine Size: 1.4 (8v)
Fuel Type: Diesel
Mileage: 100000
Trim Level: Desire
Gearbox: Manual 5 speed
DPF: Yes
LHD or RHD: RHD (UK)

Post

thanks Arfur i will look into the injectors. the car has had the problem since we bought it a few wks ago i have just got a manual for it so looks like i have got some fun ahead :lol: :lol:
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User avatar
My Name: Arfur Dent

Guru
Posts: 3520
Joined: Sat Jul 23, 2011 3:47 pm
Model: C3 2002-2005, Original shape model
Year: 2002 (52)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 100000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
Has thanked: 345 times
Been thanked: 135 times

Post

rickyc1977 wrote:thanks Arfur i will look into the injectors. the car has had the problem since we bought it a few wks ago i have just got a manual for it so looks like i have got some fun ahead :lol: :lol:
Hi rickyc1977, how are you getting on with the Diesel?
You can add an avatar to your account - Avatar or change your vehicle details - Car Bio or even add a signature to your posts - Signature. But this is not all you can do in the User Control Panel :)
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