Will not start

i have been following several post as i trouble shoot the starting circuit with no luck. Battery fully charged, all fuses are good, starter relay checks good, replaced NSS, also done continuity test on this new NSS (checks good). i have 12.48v to the connector at the NSS and good gnd. tried adjusting the NSS. no start. i also found a broken wire #9 L-W (neut) at the back of the connector. i am starting to suspect the immobilizing circuit. Can anyone help?

 

Cranks but no start?

 

If your saying the starter is not engaging the immobilizer has nothing to do with the starting circuit, the starting circuit is very simple on 2nd gen trucks (2 fuses (AM2 and STA), ignition switch, neutral safety or clutch safety, starter relay, wiring, and starter.
Easiest checks can be done at the STA relay with a test light (test light connected to ground pins 1 & 5 should have power when you have someone try to start it) (test light connected to battery positive pin 2 should be constant ground, pin 3 should light the light as well if the circuit is good to the starter.)

 

no crank. no power to the starter when starting position. starter cranks if i jump the relay. i will test the 1 & 5 at the relay as stated and follow up. thanks.

 

This might help with pin # @ the fuse box.

 

no i have not fixed the neutrl wire. it separated from the back of connecter to the nss. ordered new connector or will try to repin. not getting 12v to 1@ to close the starter relay. gnds. test good.

 

Pin 1 is from the STA fuse and goes though the clutch safety switch.
Do you have power on both sides of the STA fuse with the key in the crank position?
Do you have a Clutch Start Cancel switch?

 

He has an automatic if he is checking the NSS Switch.

Fix the connector wiring then check out the signals for Park and Neutral.

Thanks @caribe makaira for the drawing schematic.

 

I guess I misread the post, I swore I saw clutch switch mentioned when I read it yesterday

 

no clutch safety switch. no power on either side of sta fuse. no power at the start relay. all grounds seem good.

 

If your AM1 fuse is good you need to check the black/white wire at the ignition switch for power with the key in the crank position. If you have no power then check the white/blue wire from the AM1 fuse, if it has power but you have no power coming out on the black/white wire while the key is in the crank position you have a bad ignition switch.

 

i removed the connector to the ignition switch and have power at the white/blue. no power from the blk/wht. i will try to test by reconnecting the connector and probe from the back as i turn the key to start.

 

Started from the beginning today. 7.5A fuse and relay test good.
12v to the start relay #5 in the start position.
12v to one side of 7.5A fuse term. (blk/wht).
NO VOLTS OR GND. TO THE OTHER SIDE OF THE 7.5A term. (v wire).

ignition switch test:
wht/blue 12v constant.
blk/wht 12v @ start pos.
yell/grn 12wv acc & on positions.
blue/wht 12v on & start positions.

 

continue to t/s the no crank condition. i believe it has a large voltage drop when leaving the 7.5a fuse. trying to locate all the connectors as per wire schematic. to test for voltage and continuity. can anyone help me locate the 2A & 2B connectors and location of connector E10 @ ECU.

 

It’s “hidden”. See step 6 & 7 here
https://www.tacomaworld.com/threads...-box-battery-wire-replacement-upgrade.420450/

The pinout for the connectors is in post #7 above.
Best of luck to you, hope you get it figured out

 

Finally getting back to my Tacoma to continue troubleshooting the no crank problem.
I have 12 V DC at wire number three a connector to be and connectors PB all the way to the neutral safety switch.
I have no continuity from pin number five which is black with yellow at the neutral safety switch to ground.
Could it be possible I have an open wire or bad connection connectors to a or to be.
Also if the engine control module is involved I can you some help to locate connectors E5 & E6.
Thank you for all the help you guys have supplied so far.

 

Hang in there man. I’m working right now. But if no one gets back to you, I’ll take a look at the diagrams again once I get home.

You’re getting somewhere now.

 

Wire 5 of the PNS goes to the STA relay.
It is the control wire. Pull the relay and see if you have continuity to pin 1 of the STA relay from pin 5 of the PNS.

 

The ECM does not have any involvement in the starting circuit it only gets a start signal from the ignition switch to tell it to turn on the fuel pump, the engine should still crank over even if the ECM was unplugged.

Your saying you have power at pin 5 of the park neutral switch with the key in the start position but not at pin 1 of the STA relay?

 

Thanks @Dm93
Still not made it home.
Won’t be able to help here for a few more hours.