No Bus Error

Thumper4fun

Thumper4fun

TJ Enthusiast
Joined
Jul 16, 2018
Messages
132
Location
Gadsden, AL
I have been getting the No Bus error along with no gauges and check engine light recently. Based on my research it is a common TJ issue. I followed the steps of removing my gauge cluster and thoroughly cleaning the connectors but the error keeps coming back. I've checked for codes and what ever is causing the issue is not throwing a code. By accident I discovered that if I turn the ignition key to the position right before the Jeep cranks and wait until all the gauges activate and then start my TJ I don't get the No Bus error. Based on this would it be possible my issue is in my ignition switch or ignition cylinder?
 
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This is the exact problem I have, minus the no bus error. It almost seems like "charging a capacitor" waiting for the gauges. If waiting for the gauges doesn't work I then need to snap the 4 way flasher switch left to right any number of times. Been chasing this for years, you may be onto something? My next step was going to be gauge cluster swap, hopefully someone else can chime in on ignition switch idea.
 
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Imapepper said:
This is the exact problem I have, minus the no bus error. It almost seems like "charging a capacitor" waiting for the gauges. If waiting for the gauges doesn't work I then need to snap the 4 way flasher switch left to right any number of times. Been chasing this for years, you may be onto something? My next step was going to be gauge cluster swap, hopefully someone else can chime in on ignition switch idea.
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Have you tried my method and if so did it work for you? Sounds like we could be suffering from the same issue. Maybe working together we can figure out the root cause and correct it. Currently it is driving me nuts not being able to track down the issue and square it away.
 
The A2 pin in the C1 connector to the PCM gets power from fuse 12 in the fuse block behind the glove box. That fuse gets power from the ignition switch when the key is in both the start & run positions. And that wire to the PCM splices & also goes to the ASD & fuel pump relay coils. The PCM also needs to ground the relay coil outputs to close those relays.

Check for power getting to fuse 12 & be sure the fuse is good & getting power out. If that is all good then you will have to start tracing that wire from the fuse block to the PDC (fuse/relay box in front of the battery). The splice is near the PDC & you know the wire from the relay in the PDC to the PCM is good since backfeeding from the relay did power up the PCM. It is known that corrosion at splices & terminal ends can cause issues like broken wires so if the wiring is suspect start at the back of the fuse block where the fuse terminals crimp to the wires then at the splice near the PDC.
 
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Rook said:
The A2 pin in the C1 connector to the PCM gets power from fuse 12 in the fuse block behind the glove box. That fuse gets power from the ignition switch when the key is in both the start & run positions. And that wire to the PCM splices & also goes to the ASD & fuel pump relay coils. The PCM also needs to ground the relay coil outputs to close those relays.

Check for power getting to fuse 12 & be sure the fuse is good & getting power out. If that is all good then you will have to start tracing that wire from the fuse block to the PDC (fuse/relay box in front of the battery). The splice is near the PDC & you know the wire from the relay in the PDC to the PCM is good since backfeeding from the relay did power up the PCM. It is known that corrosion at splices & terminal ends can cause issues like broken wires so if the wiring is suspect start at the back of the fuse block where the fuse terminals crimp to the wires then at the splice near the PDC.
Click to expand...

I hate to deal with wiring but I'm going to give it a shot. Thanks for the detailed instructions!
 
Rook said:
The A2 pin in the C1 connector to the PCM gets power from fuse 12 in the fuse block behind the glove box. That fuse gets power from the ignition switch when the key is in both the start & run positions. And that wire to the PCM splices & also goes to the ASD & fuel pump relay coils. The PCM also needs to ground the relay coil outputs to close those relays.

Check for power getting to fuse 12 & be sure the fuse is good & getting power out. If that is all good then you will have to start tracing that wire from the fuse block to the PDC (fuse/relay box in front of the battery). The splice is near the PDC & you know the wire from the relay in the PDC to the PCM is good since backfeeding from the relay did power up the PCM. It is known that corrosion at splices & terminal ends can cause issues like broken wires so if the wiring is suspect start at the back of the fuse block where the fuse terminals crimp to the wires then at the splice near the PDC.
Click to expand...

X2, this would be my first method of approach.
 
Luckily mine went away. Since I had just replaced my O2 sensors, I went back around and squeezed them together extra tight. Don’t know if that was the cause or not but since doing that absolutely no new no bus errors
 
@Beowulf. How long between adjusting those O2 sensor connectors and posting? I am in the middle of the issue myself, it has gotten irritating driving down the road and BEEEEEP no instrument cluster... I am sure it is going to be a loose ground somewhere due to the intermittent-ness. Going through the steps took apart the dash... my dash is DIRTY So I am going to clean that and see if it fixes the problem first, I learned 3 vehicles ago, look at the cheapest possible problem first... it usually is the culprit... and don't dig any deeper then necessary... you make more work for yourself if you do LOL

Edit, asking because I had the problem for a few weeks, off and on while driving hitting bumps, I zip tied some of the connectors I thought were a little loose... the problem "went away" for 2 months... then came back.
 
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My Jeep cherokee XJ has a similar problem but some differences. First off, I would put my jeep to ON and it the only light on the cluster is airbag and brake, the check engine or check gauges should stay on with every other light but it all is off, and my battery all my gauges don't move until started. So I found a quick fix online that should work by rerouting my grounds from my gauge cluster, didn't work. So, I went straight to my PCM/ECM, I ordered a new one and they programmed it for me and said it had 0 check engine lights on. Which was a lie, it had 2 engine lights and was never programmed even after I called and confirmed. But anyways, I plugged it in and even if it isn't started I should be able to know if it, but it still had the no bus. So I'm given up. I don't know what I need to do at this point! Please help me too
 
My Jeep cherokee XJ has a similar problem but some differences. First off, I would put my jeep to ON and it the only light on the cluster is airbag and brake, the check engine or check gauges should stay on with every other light but it all is off, and my battery all my gauges don't move until started, it does start unlike some of yours it seans though. So I found a quick fix online that should work by rerouting my grounds from my gauge cluster, didn't work. So, I went straight to my PCM/ECM, I ordered a new one and they programmed it for me and said it had 0 check engine lights on. Which was a lie, it had 2 engine lights and was never programmed even after I called and confirmed. But anyways, I plugged it in and even if it isn't started I should be able to know if it, but it still had the no bus. So I'm given up. I don't know what I need to do at this point! Please help me too
 
Nakinto said:
@Beowulf. How long between adjusting those O2 sensor connectors and posting? I am in the middle of the issue myself, it has gotten irritating driving down the road and BEEEEEP no instrument cluster... I am sure it is going to be a loose ground somewhere due to the intermittent-ness. Going through the steps took apart the dash... my dash is DIRTY So I am going to clean that and see if it fixes the problem first, I learned 3 vehicles ago, look at the cheapest possible problem first... it usually is the culprit... and don't dig any deeper then necessary... you make more work for yourself if you do LOL

Edit, asking because I had the problem for a few weeks, off and on while driving hitting bumps, I zip tied some of the connectors I thought were a little loose... the problem "went away" for 2 months... then came back.
Click to expand...


After playing with my O2 sensors, the No Bus went away immediately and has not come back.
 
I have been getting the No Bus error along with no gauges, check engine light and engine cranks but won’t start recently. I have 2001 TJ with 4.0 distributor less engine around 125000 kms done. Based on my research it is a common TJ issue.

  • I followed the steps of removing my gauge cluster and thoroughly cleaning the connectors but the error keeps coming back. I've checked for codes and whatever is causing the issue is not throwing a code.
  • Checked the Crank Sensor, by removing the grip if the gauges works but still gauges didn’t responded
  • Replace/Check all the fuses under glow compartment they are good and tester glows on both ends
Can anyone guide me further in this regard?
 
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I just figured out the problem on my 2000 Jeep Wrangler Tj. There was a bad connection to the sentry key immobilizer module (SKIM). I cleaned the pins and it is working great. $0 fix.
 
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Silvioziga said:
mi trovo io in questa situazione ora è non so cosa fare…
Resta accesa luce chiave
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SE la spia della chiave rimane accesa, allora hai un problema con il modulo o la chiave dell'immobilizzatore.
Hai un'altra chiave di fabbrica grigia da usare?
SE l'altro tasto grigio non funziona; quindi il modulo immobilizer è difettoso e deve essere sostituito.
Puoi anche contattare l'esperto di ECU residente nel forum @Wranglerfix a cui puoi inviare la ECU per disabilitare la funzione immobilizzatore che ti consentirà di avviare la tua Jeep.
 
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