1997 Discovery won't start if check engine light on dash isn't on position 2 of key

1997 Land rover discovery, if i turn the key to position 2 for all the lights to come on all but the check engine light comes on. When the check engine light doesn't come on it won't start, but if it does light up it will wire right up. I think it might be a issue wit the computer getting a signal to say that everything ok.

Check the ECU for dirty wires or corrosion in the connectors. Water intrusion can often cause this issue.

Thanks for your input. I pulled out the wires on the computer in the firewall
And they looked clean and dry. I ordered today a new crankshaft sensor,
Also the disco only has 72,000 miles on it. I got it going last weekend, but when I turned it off I had to keep putting the key back in and turn back and forth before the light would turn on. Would the a bad crank sensor cause the check engine light not to come on when the key is in position #2?

Crank sensor normally just causes the engine not to start. Wiring issues causes the Check engine light issue.

Is there a seal right along the edge of the fender? It should make contact with the hood. If the seal is worn out, or not there, water can go right down on the computer.

I think there was a technical bulletin that came out for this issue years ago to, might be worth checking into.

Thanks for your help. I will check that tonight. Also when the truck does start I can turn it off and re-start it. What is strange is that truck runs great when it starts. Question-if it was a lose connection would the rover stall when I drive it? The rover was parked for about 6 years and was started and driven at least once a month. Any input on how to fix this would be much appreciated.
Thanks,
Matt

What was the cause? My 96 is doing the same thing. Will be fine for a few weeks, then out of the blue, the check engine light will not come on with the ignition and it will crank and not start. If the light comes on, all is good. It's driving me nuts!

saharatj98 said:

What was the cause? My 96 is doing the same thing. Will be fine for a few weeks, then out of the blue, the check engine light will not come on with the ignition and it will crank and not start. If the light comes on, all is good. It's driving me nuts!

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better to check them out bro. maybe fuses or need to clean it well. or might its ground. base on your model it is 96 so check them out first.




led lights

No, it's not fuses. There is one fuse for all warning bulbs and all the others work fine. The check engine lamp gets power with all of the other warning lamps through the bulb check relay. The check engine light gets it's on signal seperately from the ECM and Alarm ECU... The query here is how the ECM works. If the ignition switch only signals the ECM to run and has a direct link to the starter-will crank without the ECM telling it that it's ok- then there may be a break between the ignition switch and the ECM. No power to the ECM will obviously not turn the light on. If the ECM sends power to the starter from a signal from the ignition, then the problem is probably in the ECM or alarm. The other issue is there is conflicting answers on swapping a ECM from another 96-98 D1 to see if that is indeed the problem. Some say you can't without a dealer pairing it and doing so will not only fail to work in the affected truck, but then also fail to work when put back in the truck it came from without being reprogrammed. This makes diagnosing it tough at home if this is the case. Others say you can swap them just fine. I'm not going to try it until I know for sure. I sure do not need to tow two trucks to Land Rover and pay to have two trucks reprogrammed. I also do not want to tow the dead truck to Land Rover and pay 110 an hour to find out I need to pay 500 plus for a ECM, pay to tow it home and get a used one just to tow it back later to program it... F'ing computers...

I know I am not the only one with this issue, I've read it on other posts on a search over the net, but no one has posted an answer... I am about ready to just buy a used ECM and try it as I suspect that more than the ignition or the alarm ECU... Anyone?