ZX 1.9TD Wiring Diagram

[MattBLancs]

To help extend the search for diagrams a bit, some variants of the Peugeot 306 1.9TD used the same pump and keypad immobiliser.

From 306 manual,

Diagram 9

Is "one touch control unit" number 88, the keypad?

[MattBLancs]

Here's the "from 1997" central locking diagram (306. No mention of one touch)

Dia. 27

[CitroJim]

Have you got a 306 diagram showing the diesel pump and immobiliser wiring Matt? It may be combined with glowplug control and/or starting and charging arrangements.

'One Touch' refers to the electric windows - one touch to take them all the way up or down...

[MattBLancs]

Have you got a 306 diagram showing the diesel pump and immobiliser wiring Matt? It may be combined with glowplug control and/or starting and charging arrangements.

Good question, will have a look at lunch shortly. In fact, having just spotted what time it is (in conjunction with local rumbling noises) lunch time it is already!

'One Touch' refers to the electric windows - one touch to take them all the way up or down...

Course it is! Term was familiar but didn't twig was window related.

[MattBLancs]

Fuel shut off valve I assume is stop solenoid

Diagram 1, up to April 1997

Injection pump is item 14 on this one:

Diagram 2 up to April 1997

This mentions "anti start" but isn't a diagram for this supplied! Pump unit is number 11

Diagram 15 from April 1997

Similar on Diagram 16

Diagram 16 from 1997

again pump unit is number 11

[CitroJim]

Anti-start is definitely the keypad Matt! Thanks for those

Roger, seeing there's a connection to the oil pressure switch, check it's good. I've known pressure switches fail in both ways and if it has, it just might be inhibiting the keypad. A long shot but you never know...

A quick check is to ensure the oil warning light comes on when the ignition is initially switched on. Then try earthing the wire to the oil warning light sender...

Matt, you may have cracked it for us

[MattBLancs]

Excellent, crossed fingers for success here! Just sad that we jump off the page as that next diagram would clearly take any mystery out of what did what.

Anti-start seems such a strange term for it, sort of less commitment than "immobiliser" where it's very definitely not going anywhere. Anti-start sounds more "minimise the likelihood" of starting!

[Rhothgar]

There's a whole bunch of thought-provoking material and useful information there.

However, it does need to be treated with proper consideration. As an example, the last photo shows the pump unit and states 11b is the anti-start in Diagram 16. It's not. It's 11a as per the previous picture as per Diagram 15.

I noticed that even in my Xantia workshop manuals, yes the proper Citroen ones, that typos appear and cause confusion. The EGR solenoid electrovalve is component 1253 but in the location diagrams it is not as 1244. Typos and confusing information can creep in anywhere.

Thanks Matt for all this information. I am hoping it will be on use. At least, I can check the red and white wires for one.

[Rhothgar]

Anti-start is definitely the keypad Matt! Thanks for those

Roger, seeing there's a connection to the oil pressure switch, check it's good.

Where are you seeing this oil pressure switch, Jim?

If you mean the last photo with the pump then that switch appears to be incorrectly marked. Luckily, Matt has tagged all the photos with Diagram numbers for ease of identification.

[MattBLancs]

Yes, good point it's all information from "the book of lies" - and if Citroen information has typos then definitely need to tread carefully!

Weirdly the Citroen ZX manual's diagrams - the earlier ones I posted that look quite a bit different - do have diagram numbers. If anything isn't clear enough, give me a shout and I'll take another picture in today's sunshine

[CitroJim]

Roger, I've got it now. If you look at the black immobiliser plug on the pump, you see 4 wires. Keypad data, 12v supply and a signal from the oil pressure switch. The immobiliser will only work if it sees an initial earth on the oil pressure signal line. Meaning the engine is not running. Once running with oil pressure present, the immobiliser switches off because it looses its earth.

It will be off if it thinks it sees oil pressure due to a duff signal, faulty sender or bad wiring, it will be off and thus will not communicate with the keypad - hence red and green lights. Oil pressure is what effectively extinguishes the keypad lights when the engine is running. So check that oil pressure light and sender. The diagram is correct. Although in a Haynes manual it's a straight copy of the genuine article.

[Rhothgar]

Please can you confirm which diagram you are actually looking at Jim. One of the ZX ones or the 306 ones?

[CitroJim]

Please can you confirm which diagram you are actually looking at Jim. One of the ZX ones or the 306 ones?

This one Roger... Bottom right/middle... Item 11 is the pump and the four-way plug on its left-hand side is the black immobiliser plug.

Big black arrow pointing left saying 'Oil Pressure Switch'

Box a within the pump (11) is the pump immobiliser unit...

This mentions "anti start" but isn't a diagram for this supplied! Pump unit is number 11

mp unit is number 11

[Rhothgar]

Jim

The 4V MR connector to the solenoid has 4 VE wires to it (green). Of course, all coded so you have no idea where they come from.

If I knew where oil sensor was on ZX (sump presumably then I could load test the wire) and see if there is a resistance issue with it.

[CitroJim]

Jim

The 4V MR connector to the solenoid has 4 VE wires to it (green). Of course, all coded so you have no idea where they come from.

It's the four way BLACK connector with four black wires Roger, not the blue one

If I knew where oil sensor was on ZX (sump presumably then I could load test the wire) and see if there is a resistance issue with it.

It's on the front middle of the block near the oil filter... It has one wire going to it. You can't miss it. Disconnect the wire and earth it to the block to simulate no oil pressure...

With it and the black plug on the pump disconnected, you could check you have continuity from the send wire to the plug using your multimeter set to ohms.

I've had several oil pressure senders fail over the years, most recently on Bluebell...