DTC P0606 Control Module Internal Performance. Cadillac Concours 1997

For 1990-2009 cars
Engine Controls Components
PCM Power and Grounds
OBD II Symbol Description Notice
ESD Notice

### Circuit Description

The PCM has two internal processors: the E and the T side. They are connected together and share data on an interconnect called the SPI. The E side sends sensor data to the T side. This sensor data is checked and if the difference in readings between the two processors is too great, DTC P0606 will set.

### Conditions for Setting the DTC

#### Test Conditions

• | Valid SPI data is being received.

• | Ignition voltage is greater than 10 volts.

• | Ignition on for 5 seconds.

#### Failure Condition

MAP, ECT or TPS data varies between E side and T side.

### Action Taken When the DTC Sets

• | The PCM will illuminate the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

• | The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.

• | A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.

• | A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.

• | Use a scan tool to clear DTCs.

• | Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

### Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. This DTC indicates an internal PCM problem.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to A Powertrain On Board Diagnostic (OBD) System Check
2 | Replace the PCM. Refer to PCM Replacement/Programming . Is the repair complete? | -- | Go to Powertrain Control Module Diagnosis for Verify Repair | --