Overcoming the Fear - TCC Data PID Diagnostics Is Not as Scary as It Seems. - Motor Age - Automotive training, certification & parts info

Service Repair

Overcoming the FearTCC Data PID Diagnostics Is Not as Scary as It Seems.

Publish date: Jun 1, 2008
By: Travis Dewitz
Source: Motor Age

Email|Print|

|Save|License

« Previous

1 2 34

Take an Electronic Picture

Figure 6 By using this custom-made adapter, checking amperage on various fused circuits is quick and easy without doing any damage to the box terminals.

If any of the above tests point toward a solenoid problem, you may want to use a low amp probe while trying to operate the TCC solenoid (as in Figures 5 and 6). Is the solenoid drawing amperage? Does the waveform indicate a shorted solenoid? Is there a pintle bump that indicates mechanical movement of the solenoid? Normal amperage draws for a lot of TCC solenoids range from ½ amp to 1 amp, and some even draw up to 4 amps.

If the solenoid is drawing high amperage or is shorted, replace it. If you do not show any current flow, you will need to check for a good power supply and ground. You should also test the resistance from your test point through the solenoid and make sure the circuit isn't open. With these tests, you are able to tell if the TCC solenoid is electrically working.

Figure 7 After heating the valve body, I was able to get the TCC valve to start sticking in its bore.

Now you should be able to determine if TCC slippage is an electrical or mechanical TCC solenoid fault. If your testing proves that the solenoid and control circuit are electrically sound and the solenoid "clicks," you know you have either an internal transmission fluid leak, fluid blockage, a binding or leaking valve (as in Figure 7), or a torque converter failure.

Don't Be Afraid of the Unknown

Reader Interest Survey

Testing and diagnosing a lot of TCC systems is no different than any other system on a vehicle once you know how it works and what to look for. What helps me get a good handle on any automotive system is looking at a lot of known-good data. Seeing how different systems work without any problems will help you find problems much quicker and more efficiently.

When you get that next TCC-related code, remember to consult your information source for that vehicle's TCC operation characteristics and code-set criteria. There are many different TCC systems out there, but this should get your foot in the door. Don't be afraid of the unknown in the pursuit of knowledge with the tools and knowledge you already possess.

Travis Dewitz works full time for Dewitz Truck and Auto Repair in Eau Claire, Wisc. and also runs his own mobile diagnostics business, Dewitz Diagnostic Solutions. Travis is an ASE Master Automobile Technician and has other ASE certifications including L1. You can contact him through http://www.dewitzauto.com/.

« Previous

1 2 34

About the Author

Travis Dewitz

Articles by Travis Dewitz