Once floored loosing all communication

RADZIO · 09-03-2019, 08:12 PM

Strange issue, 3rd mechanic cant seem to find resolution.
Upon flooring the gas the car goes perfectly up to 5000rpm
and than it stops communication for few seconds changes the present
gear to a higher one and continues to drive. Its like
its putting itself into a safe mode by not wanting to pass 5000rpm
No check engine light on!
upon scanning the car getting codes with communication
error: like: lost communication with radio, amplifier,
dash. U0078, U0170, U0140, U0155, U0151,
U0233, U0184
When driving the car and pressing the gas slowly
it will pass 5000rpm and change the gear higher
normally. Issue comes when power steps in.
Car goes stupid, loosing all communication.
Battery and alternator charge normal.
Replaced TCM just to be sure, no change.

cmitchell17 · 09-03-2019, 08:35 PM

Broken motor mount? Pulling on a wire somewhere when the motor moves? Open hood and brake stand while looking at motor see if there is excessive movement?

cbr1100xx · 09-03-2019, 09:14 PM

What does "loosing" mean?

6spdhyperblue · 09-03-2019, 09:31 PM

Check the wiring harness near the rear tires and the one under the coolant reservoir for rubbing and melting.

Third mechanic means it’s not going to the dealer? You have headers?

red_johnny · 09-04-2019, 03:46 AM

Quote:

Originally Posted by 6spdhyperblue

Check the wiring harness near the rear tires and the one under the coolant reservoir for rubbing and melting.

Third mechanic means it’s not going to the dealer? You have headers?

I agree. Likely a melted harness, could be a loose ground. Headers would explain it if you didn't pull back and secure the harness that runs close to it or the plug wires (or single wire) grounding on the headers.

RADZIO · 09-06-2019, 09:00 PM

Quote:

Originally Posted by 6spdhyperblue

Check the wiring harness near the rear tires and the one under the coolant reservoir for rubbing and melting.

Thats Exactelly what I did today, took me good 5 hours to disconnect
and check every cable for loose or broken connection.
Pic attached.

Third mechanic means it’s not going to the dealer? You have headers?

No warranty so no dealer. No headers, all stock.

RADZIO · 09-06-2019, 09:03 PM

Thats Exactelly what I did today, took me good 5 hours to disconnect
and check every cable for loose or broken connection.
Pic attached.

RADZIO · 09-06-2019, 09:17 PM

So upon checking all wiring and securing it by electrical tape,
cleared the codes and went for a test run. Car on Touring mode
no issues, upon flooring the gas pedal went as it did
in the past, switching all first 3 gears at 6500rpm.
Lovely! Now, when I switched to the sport mode same issue
as before, cutting off at 5000rpm.
Also noticed that when the trans temp was
low it was shifting at high rpm, once it heated
up a bit (after driving 20-30min) it didnt want
to shift over 5000rpm.
Maybe a Silinoid in the tranny?

09-03-2019, 08:12 PM	#1
RADZIO Drives: 2018 Camaro 2SS Join Date: May 2019 Location: Waterdown Posts: 10	Once floored loosing all communication Strange issue, 3rd mechanic cant seem to find resolution. Upon flooring the gas the car goes perfectly up to 5000rpm and than it stops communication for few seconds changes the present gear to a higher one and continues to drive. Its like its putting itself into a safe mode by not wanting to pass 5000rpm No check engine light on! upon scanning the car getting codes with communication error: like: lost communication with radio, amplifier, dash. U0078, U0170, U0140, U0155, U0151, U0233, U0184 When driving the car and pressing the gas slowly it will pass 5000rpm and change the gear higher normally. Issue comes when power steps in. Car goes stupid, loosing all communication. Battery and alternator charge normal. Replaced TCM just to be sure, no change.

09-03-2019, 09:14 PM	#3
cbr1100xx Account Suspended Drives: '14 Jetta 1.8, '19 1SS Join Date: Mar 2010 Location: San Diego Posts: 886	What does "loosing" mean? Last edited by cbr1100xx; 09-03-2019 at 09:26 PM.

09-06-2019, 09:03 PM	#7
RADZIO Drives: 2018 Camaro 2SS Join Date: May 2019 Location: Waterdown Posts: 10	Thats Exactelly what I did today, took me good 5 hours to disconnect and check every cable for loose or broken connection. Pic attached. Attached Images

09-03-2019, 08:35 PM	#2
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,201	Broken motor mount? Pulling on a wire somewhere when the motor moves? Open hood and brake stand while looking at motor see if there is excessive movement?

09-03-2019, 09:31 PM	#4
6spdhyperblue Drives: 6th gen Join Date: Aug 2013 Location: US Posts: 3,675	Check the wiring harness near the rear tires and the one under the coolant reservoir for rubbing and melting. Third mechanic means it’s not going to the dealer? You have headers?

09-06-2019, 09:17 PM	#8
RADZIO Drives: 2018 Camaro 2SS Join Date: May 2019 Location: Waterdown Posts: 10	So upon checking all wiring and securing it by electrical tape, cleared the codes and went for a test run. Car on Touring mode no issues, upon flooring the gas pedal went as it did in the past, switching all first 3 gears at 6500rpm. Lovely! Now, when I switched to the sport mode same issue as before, cutting off at 5000rpm. Also noticed that when the trans temp was low it was shifting at high rpm, once it heated up a bit (after driving 20-30min) it didnt want to shift over 5000rpm. Maybe a Silinoid in the tranny?

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