P0884 – Transmission control module (TCM) -power input signal intermittent malfunction

Mia

By Mia (Contact Me)
Last Updated 2017-02-23
ASE Master Tech

Trouble CodeFault LocationProbable Cause
P0884 Transmission control module (TCM) -power input signal intermittent malfunction Wiring, poor connection, TCM

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What Does Code P0884 Mean?

The transmission control module (TCM) can be built into the engine control module or it can be a separate unit. Proper TCM operation is vital to vehicle function. The TCM receives input from several different sensors and uses that information to determine control of various outputs, such as the shift solenoids and torque converter clutch solenoid.

An example of a transmission control module

tcm

(Courtesy: tremec.com)

Code P0884 indicates the TCM has intermittently lost either power or ground.

What are the common causes of code P0884 ?

  • Wiring problems
  • Faulty TCM or TCM programming

What are the symptoms of code P0884 ?

Symptoms associated with code P0884 may include an illuminated check engine light, harsh shifting, slippage and a vehicle that is stuck in “limp” mode.

How do you troubleshoot code P0884 ?

This code is often set in error or due to vehicle operating conditions. The first step is to clear the code, drive the vehicle and see if it returns. If it does not, no further diagnosis is currently needed. Next, check for technical service bulletins (TSBs) regarding the concern. If no TSBs are found, locate the TCM and perform a visual inspection of the unit and wiring. Repair as needed. If no problems are found up to this point, move forward with a sequential diagnosis of the system. Refer to the manufacturer’s service information for the exact diagnostic process.

It’s a good idea to obtain the factory wiring diagram before proceeding with diagnosis. Autozone offers free online repair manuals for many vehicles under their repair help section (http://www.autozone.com/repairinfo) and ALLDATA offers single vehicle subscriptions (http://www.alldata.com/oe-info-student-and-diyer).

  • This code is often set in error or due to vehicle operating conditions. The first step is to clear the code, drive the vehicle and see if it returns. If it does not, no further diagnosis is currently needed. Next, check for technical service bulletins (TSBs) regarding the concern. If no TSBs are found, locate the TCM and perform a visual inspection of the unit and wiring. Repair as needed. If no problems are found up to this point, move forward with a sequential diagnosis of the system. Refer to the manufacturer’s service information for the exact diagnostic process.

    It’s a good idea to obtain the factory wiring diagram before proceeding with diagnosis. Autozone offers free online repair manuals for many vehicles under their repair help section (http://www.autozone.com/repairinfo) and ALLDATA offers single vehicle subscriptions (http://www.alldata.com/oe-info-student-and-diyer).

    Test the power side of the circuit: Consult the factory repair information to determine the correct pins. The TCM will typically have many wires going to it, so it’s important to make sure you are testing the correct wire. To check for power, disconnect the TCM connector and set your digital multimeter to the DC volts setting. Touch the positive end of the meter lead to the B+ pin on the harness side of the connector. Connect the negative meter lead to the battery negative post. In most cases, the meter should read battery voltage. If it does not, there is problem in the power supply circuit. You will need to trace the factory wiring diagram to locate and repair the problem. Since this code is intermittent, it’s a good idea to perform this test a second time while wiggling the wiring harness to check for shorts.

    Note: Some TCMs have a B+ terminal and an ignition terminal. In this case, you’ll want to repeat this test at the TCM ignition terminal.

     

    Capture

    A typical TCM wiring diagram. In this example, power would be checked at connector pins 302 and 303. Ground would be checked at pin 360.

    (Courtesy: ASE)

  • Test the ground side of the circuit: Consult the factory repair information to determine the correct pins. To check for ground, disconnect the TCM connector and your digital multimeter to the DC volts setting. Touch the negative end of the meter lead to the ground pin on the harness side of the connector. Connect positive meter lead to the battery positive post. In most cases, the meter should read battery voltage with a negative sign in front of it. If it does not, there is problem in the ground circuit. You will need to trace the factory wiring diagram to locate and repair the problem. Since this code is intermittent, it’s a good idea to perform this test a second time while wiggling the wiring harness to check for shorts.

The TCM itself is a possible cause of this code. However, this is a rare occurrence and diagnosis can be difficult.

 

Codes Related to P0884

  • DTC P0880: Transmission Control Module (TCM) Power Input Signal
  • DTC P0881: Transmission Control Module (TCM) Power Input Signal Range/Performance
  • DTC P0882: Transmission Control Module (TCM) Power Input Signal Low
  • DTC P0883: Transmission Control Module (TCM) Power Input Signal High

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