Fault code P06AF is called “Torque Management System – Forced Engine Shutdown” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P06AF
Stored code P06AF means that the Powertrain Control Module (PCM) has detected a torque control system malfunction. The malfunction was so severe that a forced engine shutdown was required.
The torque control system is designed to reduce engine torque during automatic transmission shifting. This is necessary to increase the life of the transmission and all other transmission components.
The PCM processes data from various sensors to determine the parameters to be applied to the torque control system. Once the strategy is set, the PCM initiates it and repeats it with each applicable driving cycle.
Actual engine torque reduction is realized when the PCM delays ignition advance. If the PCM detects that ignition timing cannot be delayed or that engine torque cannot be effectively controlled. An engine stop will occur, code P06AF will be stored, and the malfunction indicator lamp will illuminate.
The engine torque control code only applies to vehicles with automatic transmission.
Symptoms of vehicle malfunctions
The main signal that an error P06AF has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- Check engine control lamp on the control panel will light up (the code will be recorded in the memory as a malfunction).
- Unable to start the engine.
- Jerking, ignition skips during engine operation.
- Problems with engine controllability.
- Poor transmission operation.
- Abrupt shifting of gears.
This error is quite serious, as it can cause problems with vehicle handling. If code P06AF is not corrected in a timely manner, serious mechanical damage may occur to the engine or transmission.
Factors that can cause this error code
The error code P06AF can mean that one or more of the following problems have occurred:
- Transmission input or output speed sensor is defective.
- Mechanical failure and transmission failure.
- Defective torque converter.
- Broken or shorted wiring or connectors.
- In some cases, malfunction of PCM or TCM.
How to fix or reset OBD-2 code P06AF
Some suggested steps for troubleshooting and fix the error code P06AF:
- Read all data and error codes stored in the PCM memory with an OBD-II scan tool.
- Reset the stored codes and test drive the vehicle.
- If the error is back, check the connectors, and check the wiring for damage or poor contact.
- Test the transmission as well as the torque converter.
- If the code is still active, the PCM/TCM most likely needs to be flashed or replaced.
Diagnose and repair of problems
Before you begin the process of troubleshooting P06AF, you should research the Technical Service Bulletins (TSBs) for your particular vehicle. In some cases, this can save you a lot of time by pointing you in the right direction.
You should then perform a detailed visual inspection to check the wiring condition for obvious defects. Check the connectors and wiring as well as the PCM or TCM.
Normal readings for wiring and connections should be 0 ohms of resistance. The wiring continuity check should always be done with power disconnected from the circuit. To avoid short-circuiting and creating additional damage.
Resistance or lack of continuity indicates faulty wiring that is open or shorted. In this case, repair or replacement will be necessary.
Transmission control module (TCM)
To check if the TCM is actually sending a signal, you will need a graph multimeter set up for duty cycle, or a digital storage oscilloscope. Connect the positive wire of the multimeter, to the wiring harness going to the TCM. And the negative wire to a good ground.
The duty cycle should be the same as the one set by the TCM in the extended readout of the diagnostic tool. If the cycle remains at 0% or 100% or is intermittent, check the connections again. If all wiring is OK, but error P06AF remains, the TCM may be faulty.
On which vehicles does this problem occur most frequently
Fault code P06AF can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Buick
- Cadillac
- Chevrolet
- Ford (Focus)
- GMC
- Honda
- Jaguar
- Mercedes-Benz (W212)
- Volkswagen
Fault code P06AF can sometimes be found with other errors. The most common are the following: P2637, P2638, P2639, P2640.
