996 no start / no crank - am i missing something?

[Wolfsrun]

Good afternoon all,

This is my first post but want to start by thanking all who have shared there knowledge on other posts as it has allowed me to fix various items on my car.

 

looking for assistance before i take the car to the dealer. i think it is down to the mobilizer but not sure if there is something easy i am over looking.

currently have a no start / no crank condition. when i pulled the car out of winter storage it would crank slow but not start.

1) Replaced the battery, still no start. Then turned into no crank.

2) Replaced ignition switch, started and ran for 10 -15 minutes; but would not restart.

3) Have 12V to pin 30 of the starter relay when key turned to start. And if i short pin 85 (from DME) to ground it cranks but wont start.

4) Replaced Starter relay with a new one. Will "click" when key turned but not hold.

5) swapped the DME relay with another one. (read a post somewhere that this fixed a similar issue for someone)

6) bypassed clutch switch

7) very occasionally (1 out of 40 to 50 tries) car will fire up. this may coincide with having the battery disconnected for 30+ min first but is not guaranteed.

? removed the control unit under the seat and when open appears to be in good condition, no moisture / corrosion. 15 amp fuse confirmed good.

9) checked all fuses in driver foot well, no issues found.

 

have tried both keys with the same results.

At this point i think either the immobilizer or ECU are the problem but do not have an appropriate scan tool for either of these.

can any of you recommend something i should try before going to the dealer?

 

 

[JFP in PA]

15 minutes ago, Wolfsrun said:

Good afternoon all,

This is my first post but want to start by thanking all who have shared there knowledge on other posts as it has allowed me to fix various items on my car.

 

looking for assistance before i take the car to the dealer. i think it is down to the mobilizer but not sure if there is something easy i am over looking.

currently have a no start / no crank condition. when i pulled the car out of winter storage it would crank slow but not start.

1) Replaced the battery, still no start. Then turned into no crank.

2) Replaced ignition switch, started and ran for 10 -15 minutes; but would not restart.

3) Have 12V to pin 30 of the starter relay when key turned to start. And if i short pin 85 (from DME) to ground it cranks but wont start.

4) Replaced Starter relay with a new one. Will "click" when key turned but not hold.

5) swapped the DME relay with another one. (read a post somewhere that this fixed a similar issue for someone)

6) bypassed clutch switch

7) very occasionally (1 out of 40 to 50 tries) car will fire up. this may coincide with having the battery disconnected for 30+ min first but is not guaranteed.

? removed the control unit under the seat and when open appears to be in good condition, no moisture / corrosion. 15 amp fuse confirmed good.

9) checked all fuses in driver foot well, no issues found.

 

have tried both keys with the same results.

At this point i think either the immobilizer or ECU are the problem but do not have an appropriate scan tool for either of these.

can any of you recommend something i should try before going to the dealer?

 

 

 

Welcome to RennTech

Without the proper diagnostic tools, you are chasing your tail and just swapping parts.  Take the car in.

[Wolfsrun]

JFP, thank you.

That is what i thought but figured it was worth asking.