Non starting in Park

[Rickshaw]

This is a 75 diesel Auto problem that , over past couple of weeks , has been growing.

To start these cars they need to be in Neutral – will not if in Drive etc. Recently my car has increasingly refused to start in Park. Sometimes I had to repeatedly move it into ‘D’ or 4 etc , then back to ‘N’ before it would start but today it repeatedly refused. It is as if it fails to recognise it is in N. This may be a need for some sort of cable adjustment ? or whatever. I am not a technical person in this area and would therefore appreciate some pointers as to likely cause and where to start looking.

On a related aspect , I have not – yet – managed to locate a source for new 75 diesel Auto cables - although good old DMGRS now have new cables for Manuals ( could you get them for Autos DMGRS ?) . Meanwhile , if anyone knows a source for 75 Auto cables I’d appreciate details. As a backup I have purchased a second hand one from a breakers.

Fortunately I have two other 75’s in excellent condition so I’m not car less but I will get this Auto back to full health because it is a real pleasure to drive – as all 75’s are !

Anyway , your advice is eagerly sought !

All the best.

[bigblue75]

Hi Roger, having issues with gear selection on an 05 cdti auto- ( https://the75andztclub.co.uk/forum/s...61#post2949461 ) had started a thread on it today. Mine has always been happy to start in Neutral or Park and before today was performing faultlessly.
I have posted a link to a single post which is a sort of how to adjust the selector cable, not sure if that's any help to you?

Will watch both yours and my thread with interest and update accordingly.

[Rickshaw]

Thanks for the posting and the reference to your other thread – Arctics notes are , as usual , a really useful reference. Your problem does look much like a cable adjustment issue and I very much hope other people with knowledge about our Autos will add more value to both of our threads.

As regards mine , I am now wondering whether I have an electrical problem associated with the gear mode switch located below the gear stick eg :-

Poor contact on the ‘N’ position either in the physical end of gear select mechanism failing to a circuit to the mode switch or mode switch to ignition switch loop?

I’ll look at the circuit diagrams and also try to find a source for a new/replacement mode switch.

If anyone knows of a source please advise. Would they have been in the Chinese versions of our cars and might good old DMGRS be able to source some ?

All the best.

[Rickshaw]

First - have just tried car start again. Each time ensured in 'N' and waited for glow plug sign to extinguish as you should. Three times ignition did nothing , then once started with a bit of turnover - only to stop !

Second , have scanned other threads , finding following mentioned :-

1 - A worn / collapsed engine mount may cause selector problems. How? I HAVE been getting growing engine bay knocking - suspect suspension .

2 - a bad 'cable alignment' at the gear box end can cause selector problems at the Gear knob end. Not sure how you identify this as being the problem but it is suggested you need a special tool to readjust the cable end. Do not think this is something I am well versed in so would really want someone with better experience on these 75 Auto's to do this .

Does anyone know such a person / garage within range of me in Guildford - or nearest to me. Quite happy to get the car there. PhilT4 are you still about ?

[patrolman pete]

Could also be the starter solenoid contacts. On my manual diesel it used to start to crank then stop whilst the key was still turned!

[SD1too]

Hello Roger,

When you select 'R', do the reversing lights illuminate reliably every time?

Simon

[Rickshaw]

Well , a thanks to you last two chaps – some comments :-

1 - Patrolman pete – I too have been wondering if this all comes down to a Starter solenoid contacts issue that would arise on N or P . I am going to investigate
2 - SD100 – Simon , appreciated that idea and checked. Yep , when in R the reversing lights do come on. Pushes me more along the lines of the Starter a above.

Now one thing this problem HAS got me into is a better understanding of some issues on the Automatic side eg technical / mechanisms and logistics. On the latter I now have a spare gear cable and its gear shift unit with gear stick.

BUT I do like to understand ‘mechanisms’ and there is one in particular I cannot find guidance on anywhere ( looked all over the web , at past threads on our club etc etc) . It is this :-

• Where is the signal taken from that sets the appropriate red light on the AUTOMATIC GEAR SELECTOR INDICATOR beside the gear stick ?
• Over and above this there will also be some connection to enable / disable the Ignition switch – and I am sure signals also reach logic elements like the ECU.

At first I expected some sort of sensor at bottom of the gear stick – but no obvious evidence. Maybe on the Gear box end ?

This is not an area I have really gone into before but it DOES help to know about these things/ how they work – and where documentation resides - sometimes before embarking on tasks BUT I have hit a brick wall.

I’m sure I am not alone -SO , can anyone out there give me ( and others ) some enlightenment ? How does the 'sensing' work , where is the gear position sensed , where do the signals go / wires run eg to the Selector Indicator ?

Here’s hoping someone knows!.

[bigblue75]

https://www.the75andztclub.co.uk/for...93&postcount=8

Although extracted from a Landover document, and part two was never posted.... There's a lot of good relevant info on the autobox.

[genpk]

it will be you actuator switch which sits on top of the auto box,pull the airbox out
and you will see it.The cable running from it has a plug point on the front of the engine that can also cause issues as it can come apart.
You can disassemble the switch and clean it as it fills up with oil from the throttle body dripping on it.
Only thing to remember is to mark the position of the switch prior to removing it as it has an adjustment.

[SD1too]

Hello Roger,

With reference to RAVE, I may be able to help answer some of your questions.

Originally Posted by Rickshaw

• Where is the signal taken from that sets the appropriate red light on the AUTOMATIC GEAR SELECTOR INDICATOR beside the gear stick?

The red LEDs are supplied directly from the main relay via the gear selector contacts within the inhibitor switch. No ECU is involved in the LED circuits.

Originally Posted by Rickshaw

• Over and above this there will also be some connection to enable / disable the Ignition switch – and I am sure signals also reach logic elements like the ECU.

The automatic transmission ECU is wired in parallel with the gear selection LEDs. It therefore knows every position set by the selector lever.

Originally Posted by Rickshaw

... where is the gear position sensed , where do the signals go / wires run eg to the Selector Indicator ?

The gear selector lever position is "sensed" at the automatic transmission ECU. Positions 'P' & 'N' are also sensed by the Immobiliser ECU via dedicated contacts in the inhibitor switch.
The wires run directly from the inhibitor switch where they split via a splice. One leg goes to the selector (LED) indicator and the other goes to the automatic transmission ECU.

Any help?

Simon