Q: Check Engine Diagnosis - Transmission controller Communication error codes

asked by on August 26, 2016

Check engine light came on. Transmisson would not shift from low gear. Speedometer was not registering. Stopped and restarted car. Car operated normally. Check engine light went off. Car has been operating normally. Took car to Autozone. Following was reported: P0700(indicates transmission control system). Error Codes Read P0700 (Read Fault memory of control unit ETC; U0101 (Lost communication with TCM); P1603 (PCM Internal dual port RAM communication failure; P0882 (TCM Power input signal low); P0461 (Fuel level sensor A Circuit range/performance). Car has been operating normally for about a 7 weeks but am concerned that problem may return. Advised that transmission controller may need replacement. Your opinion is appreciated.

My car has 78079 miles.
My car has an automatic transmission.

Check Engine Light is on Inspection $94.99 - $114.99 Get a Quote

Hello there, many different faults can cause this combination of codes on your 2006 Chrysler PT Cruiser.

When we see loss of communication codes with Transmission Control Module (TCM) internal faults, this usually means one of the following:

  • the TCM is failing
  • the TCM is not being supplied with enough power
  • the wiring to the TCM is faulty

Given that you have fuel codes as well, the first place a qualified technician should check is the battery, and to inspect the wiring of the vehicle. Then a Check Engine Light inspection should be done to asses the codes.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

OK my car was stalling out so I started checking the obvious battery alternator plugs wires not the problem
Start by checking power to the relay. If there is no power to the relay this would suggest you have either a bad wiring problem to the relay or potentially a bad ECU driver that supplies the power to the...
Possibly timing. 1998 Saturn SL2
Hi there - yes, it is possible that the engine has "jumped time" (https://www.yourmechanic.com/question/timing-chain-misaligned). This engine is known for timing chain stretch, and jumping time with higher mileage. If you have spark, fuel injectors spraying, and compression, this could be...
Engine won't accelerate past 1000 RPM's
Your car is designed to limit the throttle opening when it detects a major failure in one of its systems. What has failed would not be known since the lights you have on could have been caused by hundreds of...
Porsche Cayenne S 2005 has code P0349 read on scanner.
Hi there. The Camshaft Position Sensor tone ring could be damaged or there could be an electrical problem with the electrical circuit with the camshaft position sensor harness. I recommend replacing the camshaft position sensor (https://www.yourmechanic.com/services/camshaft-position-sensor-replacement). If you need further...
Chrysler 300 2005 abs not working. Code c2116. Does this mean my abs pump is dead for sure? Or could it be abs sensors.
Hi there. Take a digital volt meter and check the voltage on the harness to the ABS control motor. There should be a battery voltage present. If the voltage is low, then there is a break in the wiring from...
How can I turn the back windshield wiper off?
Hi Sam. Thanks for sending in your question today. It's quite possible that you have an electrical short or perhaps a stuck open or damaged electrical relay that is activating the wiper when the brake pedal is pressed. As such,...
I have a Chevy Traverse 2009 that is reading All Wheel Drive Off and when I brake you can hear a sound similar to a helicopter. Sh
This type of problem can be diagnosed by a mobile mechanic, right at your location. If there is a tremendous amount of noise on braking, you should have the car inspected as soon as possible. Without an actual physical inspection...
I live in Florida and last week it was forecast to have freezing temps for a week or so...Anyways,I could not afford the antifr
If you are running straight water in your cooling system then you are taking the chance the water will freeze in the motor and cause damage to the engine and cooling system.

Related articles

P0642 OBD-II Trouble Code: Sensor Reference Voltage “A” Circuit Low
P0642 means there is an abnormally low voltage reading within the "A" circuit often due too a faulty engine control module or other malfunctions.
P2700 OBD-II Trouble Code: Transmission Friction Element "A" Apply Time Range/Performance
P2700 means the transmission friction element application needs attention, possibly because of a leak in the transmission or defective pump.
B1928 OBD-II Trouble Code: Air Bag Safing Sensor Output Circuit Failure
B1928 means there is an electrical short in the air bag safing sensor, likely due to a defective electrical component or sensor.