LX470 (1999) Crank/Won't start (1 Viewer)

[anewham]

Hi folks, long time reader here (although only just registered), great post on suspension that fixed Bucking Bronco issue and replace my accumulators (saved me $$$'s).

So my 1999 LX470 cranks but won't start (250K miles). Symptoms are as follows:

- Has intermittent start issues, but not won't start 100% of the time. (past issues difficult to diagnose due to location/other drivers own household)
- When key inserts/security key light on center console does not stop flashing
- Tried with a second key, it still does not stop flashing
- Check wiring around the ignition column/switch and any wires loose to amplifier/coil
- Inserted scantool, fails to establish a link

Things tried so far:
- Check all fuzes on the engine compartment fuse box and the foot well fusebox. Nothing is blown
- Read thread on crank/does not start and the fuse bypass. Have jumped /bypassed the fusebox for the main relay in case I have the fusebox issue. No change in symotoms
- Pulled the main relay/tested - no issues. 12v in input causes audible click and open changes to 0ohm on output
- Repeated the same test for both IGN1 & IGN2 relays. No change of symptoms
- Pulled the Engine ECU from behind the glove compartment (I tired to buzz out power but don't have the right wiring diagram)
- With Engine ECU out, still unable to get a link from the scantool (does this mean another ECU on the scan bus is killing the link?)
- With Engine ECU, did a visual of the circuit board, can't see anything obvious.

Any other suggestions? Wasn't able to see where the key ECU, supposed to be up above the Enginee ECU?

 

[anewham]

Hi folks, long time reader here (although only just registered), the great post on suspension fixed my Bucking Bronco issue when I replaced the accumulators (saved me $$$'s).

So my 1999 LX470 cranks but won't start (it has 250K miles). Symptoms are as follows:

- It previously had intermittent start issues, but now it won't start 100% of the time (past issues were difficult to diagnose due to location/other drivers in household at time of failure)
- When the key is inserted, the security light on center console does not stop flashing
- Tried with a second key, but the light still does not stop flashing
- Checked wiring around the ignition column/switch for any loose wires near the antenna coil
- Inserted scan tool, which is unable to establish a link (checked on a second vehicle and tool works fine). Also tried paper clip in DLC1/diag port to get instrument cluster flash codes. Nothing

Things tried so far:
- Checked all fuses on the engine compartment fuse box and the foot well fuse box. Nothing is blown
- Read thread on crank/does not start and the fuse bypass. Have tried jumping /bypassed the fuse box for the main relay in case I have the fuse box issue. No change in symptoms
- Pulled the main relay/tested - no issues. 12v in input causes audible click and open changes to 0ohm on output
- Repeated the same test for both IGN1 & IGN2 relays. No change of symptoms
- Pulled the Engine ECU from behind the glove compartment (I tired to buzz out the power but don't have the right wiring diagram)
- With Engine ECU out, still unable to get a link from the scan tool (does this mean another ECU on the scan bus is killing the link?)
- With Engine ECU, did a visual of the circuit board, can't see anything obvious.

Any other suggestions? Wasn't able to see where the transponder ECU, supposed to be up above the Engine ECU?

Fixing grammar/typo's (sorry don't have edit permissions yet) - amended in the quote above

 

[anewham]

My bad, looks like I do have the fuse box issue. I had originally tried jumping E & F of the main relay, but not F direct from battery. The no link on the scan tool threw me. When I jumped F direct from battery the security light went out/started.