ChaseTruck
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Well, if there’s indeed a kill switch, then even the freshest set of fusible links won’t do much I suppose.
But changing fusible links on an 80 is a rite of passage
New to the site with an 80 series LC, it cranks, but does not start. Having fun chasing the issue. (1 Viewer)
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But changing fusible links on an 80 is a rite of passage
- Thread starter
- #22
I have not found anything that resembles an alarm. I have dissassembled most of the dash following wires, ensuring no damages, etc. Thank you!
- Thread starter
- #23
I found the kill switch button and it works as expected. When active, nothing happens, not even a crank. When turned off, it goes back to crancking with no start, no CEL. Waiting delivery of the fusible links and cleaning behind the dash. Thanks!Well, if there’s indeed a kill switch, then even the freshest set of fusible links won’t do much I suppose.
But changing fusible links on an 80 is a rite of passage
Please keep in mind that the starter circuit is separate from almost every other circuit on the vehicle. It has nothing to do with the ECU or any of the EFI components. It will have no effect on the CEL.
As posted in several other threads:
Below is a cursory check of all 3 fusible links in system. This assumes an unmolested OEM configuration.
FL AM1 - Dome lights working?
FL AM2 - When you turn the key to ON does the CHARGE LAMP light up?
FL MAIN - Brake lights working?
If yes to all 3, then all 3 fusible links are intact.
From another thread previously mentioned:
Fusible links are the very first thing to check (see above), followed by the 15 amp EFI fuse in the relay box on the left fender, followed by the 7.5 amp IGN fuse in the fuse block by the driver's left knee.
Use a meter to check fuses/links, not your eyeballs.
Once again, this engine WILL NOT RUN without the CEL illuminating with the ignition key in the ON/RUN position before cranking the starter. The CEL in that position is telling you that the ECU is not in a "ready" state and the engine will not fire. Don't even bother cranking the starter.
- Thread starter
- #25
Thanks for the post. My dome lights are working. When I turn the key, the charge lamp does not light up. The brake lights do work.
Still waiting for fusible links to be delivered.
One thing, I was checking all fuses again and noticed that the #3 fuse in the passenger compartment is missing along with the brass connectors. Can someone please confirm if this fuse exists in your truck? Thanks in advance!
If you download the Toyota factory service manual (FSM) and electronic wiring diagrams (EWD) from the resources section, all of your questions will be answered.
From the 1994 EWD:
maybe check the park/neutral switch connection to the harness? It's the pie slice shaped thing on the RH side of the transmission housing. The connector to the rest of the wire harness is somewhere near on top of the starter.
Common failure point -- water gets in and the pins and sockets corrode to dust. You can't get the whole connector anymore but you can get repair wires that already have pins and sockets crimped on. You may want to invest in some terminal picks.
Common failure point -- water gets in and the pins and sockets corrode to dust. You can't get the whole connector anymore but you can get repair wires that already have pins and sockets crimped on. You may want to invest in some terminal picks.
- Thread starter
- #28
Latest update, found that the distributor is not getting power. FSM here I go....
The distributor has a 4 pin connector. All 4 pins run back to the ECU. Where are you looking for power?
- Thread starter
- #30
Thanks Jon! According to the manual, the wires go to G1, G2, G-, and NE in the smallest connector in the ECU. I plan to start there when the rain stops, hopefully Saturday.
You will not find +12 on any of those pins. Those are the pick up coils inside the distributor that feed the ECU. They simply develop pulses that the ECU re-times according to various sensor inputs. The ECU then feeds these re-timed pulses to the igniter, which in turn feeds the primary of the ignition coil. The secondary of the ignition coil feeds the high voltage (spark pulses) to the distributor rotor.
You are starting in the wrong place for troubleshooting. You need to find the cause of the lack of the CEL with the ignition key in the ON/RUN position. I would be checking the most common issues, which have already been mentioned in the 2 threads that you have been directed to.
1. Fusible links
2. 15 amp EFI fuse: this feeds +12 to ALL of the EFI sensors and circuitry through the EFI MAIN relay
3. 7.5 amp IGN fuse
4. EFI MAIN relay
+12 at the ECU:
Constant +12: E7 pin 2
Ignition switch ON/RUN: E7 pin 13
Ignition switch ON/RUN EFI relay closed: E7 pin 12
1. Fusible links
2. 15 amp EFI fuse: this feeds +12 to ALL of the EFI sensors and circuitry through the EFI MAIN relay
3. 7.5 amp IGN fuse
4. EFI MAIN relay
+12 at the ECU:
Constant +12: E7 pin 2
Ignition switch ON/RUN: E7 pin 13
Ignition switch ON/RUN EFI relay closed: E7 pin 12
- Thread starter
- #33
I appreciate the info. I have checked the links that have been shared and verified these:
1. Fusible links - Replaced with new ones.
2. 15 amp EFI fuse: this feeds +12 to ALL of the EFI sensors and circuitry through the EFI MAIN relay - Pulled/replaced fuse and verified +12 on fuse
3. 7.5 amp IGN fuse - replaced fuse and verified
4. EFI MAIN relay - replaced and verified +12 on connectors.
Also brass bolt #4 in relay/fuse box
and B1 port of diagnostic module
+12 at the ECU:
Constant +12: E7 pin 2 - verified
Ignition switch ON/RUN: E7 pin 13 - verified
Ignition switch ON/RUN EFI relay closed: E7 pin 12 - verified
All of the above check as expected. The fuse box in the cabin also checks ok, I went ahead and replaced all the fuses there too.
OK, moving on to ECU ground points.
E10 pins 13, 24, 26
Have you removed the AFM connector by lifting the spring clip on the connector, NOT by removing the 2 screws on the connector housing, to see if the CEL illuminates with the key in the ON/RUN position?
Also, since this vehicle has an unknown history, what is the part number for the ECU? I ask this because both versions of the 1FZ-FE (OBD1 and OBD2) have the same 4 connectors with the same number of pins, but are not compatible.
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- Thread starter
- #35
Thanks Jon!
For the E10 connector, I will check the ground when rain stops, it's a pain since it's not in the garage.
I have not removed the AFM yet, but I have read the $$$ stories of removing the screws. Some have managed to solder the pins though. I will try removing it by lifting the spring clips next.
The ECU photos are attached.
- Thread starter
- #36
Tested pins 13,24, and 26 in E10 for ground. Two tested 0.0 volts, except for 24, tested 0.01.
I removed the AFM by pulling the spring clip. Tried the key on the On position, still no CEL.
I am going to re-test all the fuses and relays in case I missed anything. Else, I think I am going to look for another ECU.
- Thread starter
- #37
Now on the re-test, There is no power on Ignition switch ON/RUN: E7 pin 13 and Ignition switch ON/RUN EFI relay closed: E7 pin 12, this with the key on the ON position. For Constant +12: E7 pin 2, I am seeing +12 on pin 2 with the key out of the ignition. All other fuses and relays check ok.
No power on pins 12 and 13 point to C8 and 50A AM1. These are next on my list to check.
No power on pins 12 and 13 point to C8 and 50A AM1. These are next on my list to check.
- Thread starter
- #38
Pulled C8, after testing it, found resistance between the pins. AM1 tested ok. Ordering a replacement for C8.
That is not the correct way to test for a good ground. You want to test continuity to ground from those pins, not voltage.
Please explain "C8". I don't see that anywhere.
50 amp AM1 is not in the circuit that we're discussing. If 50 amp AM1 was an issue, the starter wouldn't crank and you would not have power to the majority of fuses in the fuse box by the driver's left knee.
The power to E7 pin 13 comes from fusible link AM2 through the ignition switch and through the 7.5 amp IGN fuse.
The power to E7 pin 12 comes from fusible link MAIN which feeds the 15 amp EFI fuse, then the closure of the EFI relay feeds E7 pin 12.
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