Fault code 1352

[Steve Walsh]

Hi

Can someone explain why the code P1352 Fault Pre Post heating relay is always present and is there a cure, Read a few posts and appears to be a common fault but it can't have rolled off the production line with it.

Not sure on the UK MOT rules but here in France they read OBD Codes as part of the test and it goes down as a minor fault,

I would rely like to clear it

Steve

[moizeau]

Both mine have 1351, glow plugs / relay etc. The 407 didn't have it originally but it's turned up recently, the Jumpy has had it ever since I owned it. I was thinking of checking the glow plugs but they can fall apart on removal apparently. They are rarely used anyway so I've left mine as is. As you say, it's noted as a 'sans contre visite' so I'm not planning on touching mine.

[wheeler]

Yes you most likely have a glow plug or 2 gone down, as the engines are not reliant on glow plugs for starting unless its way below 0 degrees there are no noticeable symptoms of the fault hence the reason why the code is in most of these cars.

[GiveMeABreak]

This specific fault P1352 relates directly to the Pre / Post Heating Relay Box. Pre-heating relay circuit: Coherence - Relay not supplied and plugs supplied. The information from the preheating control unit indicates that the relay is closed even though the ECU commands the opening of the relay for 5 seconds.

This is not to be confused with other pre-post heating fault codes.

This fault, whilst active can cause:

• Deactivation of the speed limiter
• Deactivation speed limiter until the next time the ignition is switched on
• Deactivation of the cruise control
• Deactivation cruise control until the next time the ignition is switched on
• The ECU limits the fuel flow

Resulting in:

• Lack of power
• Noise
• Jerking/stalling
• Starting problem

Suspect Areas:

Pre-heater plug, Electrical harness or Pre/post heating relay.

[Steve Walsh]

Thanks for that info, There is no symptoms, cruise and speed limiter all works as it should, Already changed the relay.

Steve

[GiveMeABreak]

The downgrade mode will only kick in when the fault is actually active Steve, so may reset itself when the ignition is turned off and on again.

[Steve Walsh]

Cheers Marc, looks like a session in my workshop, Would love to get to the bottom of it.

[moizeau]

If the code may only cause downgrade mode when active that'll be on start up or an assisted regen maybe? If you car has a FAP and it regens normally I'd ignore it. Plus if you fix it you'll be in the minority......

[wheeler]

If the code may only cause downgrade mode when active that'll be on start up or an assisted regen maybe? If you car has a FAP and it regens normally I'd ignore it. Plus if you fix it you'll be in the minority......

I would agree with that. I don't know which engine you have but if its a 1.6 HDi especially I'd leave the glow plugs well alone or you could risk opening a can of worms.
If yo want to investigate further disconnect the wires from the glow plugs & do a resistance check on each of them, I reckon you'll find one or two open circuit.

[Steve Walsh]

Can't ignore it because I know it's there !
I will be checking plugs first and then see how it goes. Probably have too much time on my hands !!

[GiveMeABreak]

He has a DW10BTED4 Wheeler.

[Steve Walsh]

To continue an old thread, curiosity got the better of me and decided to check the glow plugs. Tested them in situ and found 2 not working, After a couple of hours of very fiddly work, aided by a mirror lots of coffee, all 4 are out and waiting for the new ones to arrive.

I would love 10 mins chat with the guy who decided to put a service item in such a C**** of a location.

[Steve Walsh]

Well, the conclusion is that I am pleased it is now done, 4 new Bosch Glow Plugs fitted, all back together, Fault code now cleared,