No start, no relay activity

CRsnoop

New Member
Joined
Jul 12, 2022
Messages
3
Location
WI
2007 JKU Sahara Auto Transmission
While attempting to track down a battery drain, I did something to make my 07 not start. No crank, nothing.
1. Dash lights up, looks good.
2. All fuses are good.
3. Starter works, verified by jumping to the starter and jumping 30 and 87 at the STARTER SOL relay.
4. Battery good enough to spin the starter. Battery load tested OK, connections are tight.
5. I get clicks out of the K1 (RUN/ACCY), K2 (RUN), and K4 (RUN/START) relays, but seemingly nothing (see #6 below) out of the K3 (STARTER SOL), K5 (PCM), K6 (EBL), or K10 (ASD) relays. All of these relays are good, verified by swapping them around.
6. I do a click out of the K1, K2, and K9 (REAR BLWR) relays when moving the key from RUN to START.
7. Low voltage (about 5 volts) at the OBD port.
8. Trying to pull OBD codes via the key seems to work, but unsure because no codes are displayed before "done" is displayed.
9. Doesn't seem to be the WCM, as the fob still locks, unlocks, and alarms as expected.
10. The ignition switch/module on the left of the steering wheel does click when trying to start
11. Does not start in neutral.

I think that's everything I've found so far.
Is this the PCM?
Maybe it's something under the TIPM, given the 5V at the OBD port?
What other things I should look at?
 
I do, it comes on, but goes out shortly after when trying to start.

I had to re-hook up the battery to check this, and when I did, I got a short honk from the horn. Is that anything?
 
I do, it comes on, but goes out shortly after when trying to start.

I had to re-hook up the battery to check this, and when I did, I got a short honk from the horn. Is that anything?

Not sure about the horn honk but the light being on is your Security System. A few times the problem was a weak battery in the key FOB.