I keep getting P0778 code!
#1
Driver
Thread Starter
I keep getting P0778 code!
What is this P0778? It's critical to vehicle operation.
I cleaned the transmission speed sensors and replaced bank 1 sensor 1 O2 sensor. Now, something got unplugged. What? This thing is dead without it.
I can't seem to figure it out. Some cannon plug rear of the intake manifold?
I cleaned the transmission speed sensors and replaced bank 1 sensor 1 O2 sensor. Now, something got unplugged. What? This thing is dead without it.
I can't seem to figure it out. Some cannon plug rear of the intake manifold?
#2
What is this P0778? It's critical to vehicle operation.
I cleaned the transmission speed sensors and replaced bank 1 sensor 1 O2 sensor. Now, something got unplugged. What? This thing is dead without it.
I can't seem to figure it out. Some cannon plug rear of the intake manifold?
I cleaned the transmission speed sensors and replaced bank 1 sensor 1 O2 sensor. Now, something got unplugged. What? This thing is dead without it.
I can't seem to figure it out. Some cannon plug rear of the intake manifold?
The ECM checks for an open or short in the shift solenoid valve SL2 circuit while driving and shifting gears
Also, I saw you did an engine swap recently. Is it possible some of the ground wires aren't connected? You may want to check if some of the harnesses are loose as well. GL!
#3
Driver
Thread Starter
After I swapped the engine, I had transmission stuttering between 1-2 and 2-3. I did not use OEM fluid. I also had P0135 DTC.
Purchased new Denso O2 sensor from Amazon and replaced it.
Cleaned both transmission speed sensors and replaced fluid with Toyota T-IV. Go for a test drive, transmission is hard shifting bad, P0778. I think I messed up a wire on top of the transmission. I'm gonna dig around tomorrow AM. I bet it's a loose wire.
Purchased new Denso O2 sensor from Amazon and replaced it.
Cleaned both transmission speed sensors and replaced fluid with Toyota T-IV. Go for a test drive, transmission is hard shifting bad, P0778. I think I messed up a wire on top of the transmission. I'm gonna dig around tomorrow AM. I bet it's a loose wire.
#5
Moderator
Since you went through ALL, I would like to know where each exists.
Salim
#6
Moderator
#7
Driver
Thread Starter
Interesting enough, the 300 should not have even run after the swap. Not only was every chassis ground super corroded, I forgot to attach the bank 1 (left side, or rear) grounding strap completely.
I'm certain the P0778 is just a generic OBD code when the ECM can't figure out a ground or there is a short in the system. I used a wire brush and emery cloth to clean both sides of all engine grounds and the battery ground.
When I changed the O2 sensor, I must have moved that unattached ground.
I'm certain the P0778 is just a generic OBD code when the ECM can't figure out a ground or there is a short in the system. I used a wire brush and emery cloth to clean both sides of all engine grounds and the battery ground.
When I changed the O2 sensor, I must have moved that unattached ground.
Trending Topics
#8
Driver
Thread Starter
I found the most corrosion on the two 10mm fender well ground bolts.
The second most was the negative battery chassis ground found underneath the battery tray.
Then I found the rear engine harness not connected.
The second most was the negative battery chassis ground found underneath the battery tray.
Then I found the rear engine harness not connected.
Thread
Thread Starter
Forum
Replies
Last Post