Transmission Diagnosis

DTC P0606

Circuit Description
A normal function of the transmission control module (TCM) is monitoring the microprocessor status. When there is a microprocessor reset, the controller software will perform a power-up cycle. If a power-up cycle is performed without a power-down occurring, the controller will interpret this as a running reset. When the TCM detects that a calibrated number of power-up cycles have been interpreted as running resets, DTC P0606 sets. DTC P0606 is a type A DTC.

Conditions for Running The DTC
- No TCM DTCs P0601, or P0604.
- The ignition is ON.

Conditions for Setting The DTC
The TCM has performed 10 power-up cycles and 7 were interpreted as running resets.

Action Taken When the DTC Sets
- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL).
- The TCM freezes all ratio control functions, including the ratio control motor and desired speed ratio.
- The TCM discontinues use of the closed loop ratio control algorithm. This causes the speed ratio to be defaulted and possibly not accurate. The resulting open loop control may or may not provide optimum ratio performance.
- The TCM inhibits TCC engagement.
- The TCM commands maximum line pressure.
- The TCM no longer inhibits shifting to between reverse and drive when moving.
- The TCM turns power off to the TCC enable solenoid valve.
- The TCM discontinues torque management.
- The TCM freezes garage shift transmission adaptive functions.
- The TCM freezes main line pressure transmission adaptive functions.
- The TCM freezes torque converter clutch (TCC) transmission adaptive functions.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P0606 in TCM history.

Conditions for Clearing the MIL/DTC
- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not sent a MIL illumination request.
- A scan tool can clear the MIL/DTC.
- The TCM clears the DTC from TCM history it the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
- The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids
- Inspect the connectors at the TCM, the transmission, and all other circuit connecting points for an intermittent condition.
- Inspect the circuit wiring for an intermittent condition.

Steps 1 - 6:

DTC P0606