GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This diagnostic test checks for the loss of or invalid Instrument Panel Cluster (IPC) serial data to the PCM. When such a condition exists for 11 seconds, DTC P1604 is set.

Conditions for Running the DTC

    •  DTC P0322 not set.
    •  Engine speed 500 RPM or more for 10 seconds continuously.

Conditions for Setting the DTC

Invalid or no serial data from the IPC to the PCM for 11 seconds.

Action Taken When the DTC Sets

    •  The Malfunction Indicator Lamp (MIL) will not illuminate.
    •  No message will be displayed.

Conditions for Clearing the DTC

    •  A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
    •  A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
    • 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.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges, and Console

Go to Powertrain On Board Diagnostic (OBD) System Check