I've been reading a ton of posts here and elsewhere, several describing my exact symptom, but none giving the exact reason.

Here's what happened:

- I bought this SE7 with 185k on it
- It's been running great for over a month
- My son has an aversion to turning off the headlights when he drives it
- Next morning ... flat battery, and radio needs it's code entered

This has happened (without trouble) three times now. The latest time, however, after re-charging the battery, and re-entering the radio code, and clearing the codes in the ECU (and watching the MIL light (yellow "Service Engine Soon") turn off, so I know it's not a bad bulb):

- Turn key to Position II
- Yellow "Service Engine" (MIL) light does NOT come on
- Red "Service Engine" light comes on for 5 seconds
- During that 5 seconds, the engine will not crank
- After those 5 seconds, the engine cranks normally
- Engine does NOT fire up

- Checked and tested all fuses in both boxes
- Re-seated all the relays under the glove box
- Re-seated the connectors to both the ECU (engine compartment), and the Security controller (under the glove box)

- Disconnected the battery, left it disconnected for an hour, switched key to Position II, then reconnected the battery

- I am able to communicate with the ECU from the diagnostic port under the dash
- No codes currently present

Took the following diagnostic steps:

- Checked for spark: none
- Listened with screw driver (as if it were stethoscope) at injector for clicks: none
- Checked for fuel at pressure check point on rail: plenty of pressure

After cranking quite a while, removed one spark plug:

- No gas in cylinder
- Spark plug cool as a cucumber

Read, read, searched, searched ... Several posts recommended swapping Crank Position Sensor ... Couldn't buy the fact that this could fail at the same time as my son left the headlights on.

Coincidences do happen, so I did swap the CKS ... It was a nightmare ... the securing bolt's (there's only one on AT models) hole was stripped out. Plus the heatshield had been trashed to heck and was not re-usable. Will need to replace it.

**** DOES ANYONE KNOW THE PART NUMBER FOR THE CKS HEATSHIELD FOR A '96 DISCO SE7 WITH AUTOMATIC TRANSMISSION? ****

After re-assembly ... No change.

I think the important clues are as follows:

- No MIL light with key in Position II
- 5 second delay before it will crank the engine
- No spark, no fuel in cylinders

I've seen each of those symptoms, and several folks asking about the missing MIL light, suggesting that this is a particularly important clue (same for the 5 second delay). I could not find an explanation for what those particular clues might mean.

Please help ... I need to get the Disco out of my garage by Thursday (when my new Tesla arrives).

Mage

 

the red "service engine" light is the MIL. the yellow one is an emissions reminder. ignore it. it doesn't really mean anything.

try resetting the immobilizer switch. it is under the hood on the passenger side up by the windshield. black button. it's worth a try.

this might also be alarm related. if that is the case, i will be of no help as i have not locked my doors or set the alarm in four years.

 

Already checked Immobilizer (on firewall), should have mentioned that.

Are you sure about the MIL light? The yellow one is the one that turned off when I cleared the coders through the OBDII port.

 

Try a fresh battery, as this happened to me and the battery was toast even after recharging.

 

Sounds like the ECU to me. Whenever there's zero "Check Engine" light during a cranking it signifies the ECU is not alive. Should remain lit until the engine fires and then it extinguishes or remains lit for a MIL. Find another ECU with it's companion alarm unit (AS10) from a breaker or pick-n-pull and plug them in. Remove battery power while exchanging units and then give it another go......

Good luck.

 

I've just checked the RAVE ... I have the warning lights wrong ...

The yellow MIL light is actually labeled "CHECK ENGINE", and it was on before I reset the OBDII codes, and now it doesn't come on at all.

The other light is the red "SERVICE ENGINE", which does come on, for 5 seconds, then goes out. The RAVE says that this is the "Emission maintenance reminder"

According to RAVE: "The ’Check engine’ indicator illuminates as a
system check when the starter switch is
turned to position II and should extinguish
when the engine is started." ... This does not happen.

So ... I'm back to my original post ... MIL light does not turn on.

 

If the ECU is bad ... How am I able to communicate with it through OBDII?

 

What is a "breaker or pick-n-pull"?

 

Looks like I may have used the wrong acronym ... When I said "ECU", I meant "Engine Control Module" ... Looks like ECU refers to the alarm unit.

The ECM (part number ERR6759) is what should be controlling the MIL light, and the 10AS (not AS10) is the ECU, which is green, and it controls the alarm system.

Must these boxes be bought in pairs, or can one "learn" with the other?

Which do you think is bad? The ECM or the ECU? Or both?

 

Found a TSB including the following:

4. Use an ohmmeter to verify the continuity between the following:
^ C225 position 11 to C1032 position 22.
^ C225 position 15 to C1017 position 26.

5. Verify that neither circuit is short-circuited to vehicle ground.


Verified the connectivity between the two pairs of pins ... Also found one of the wires shorted to vehicle ground ... Replaced that wire ... No change ...

I wonder what other wires might also be damaged similarly?