P0700

Circuit Description
The Transmission Control Module (TCM) and the Engine Control Module (ECM) are connected through the serial data link circuit. The TCM sends a Class-II P-code status message to the ECM every 100 milliseconds to confirm the transmission is functioning correctly.

If the TCM detects either an A- or B-type malfunction within the transmission, the TCM will send to the ECM a Class-II P-code status message to turn the Malfunction Indicator Lamp (MIL) ON and set DTC P0700.

Conditions for Setting the DTC
- The TCM has detected either an A- or B-type malfunction within the transmission.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the freeze frame and failure records buffers.
- A history DTC is stored.

Conditions for Clearing the MIL/DTC
- The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm-up cycles without a fault.
- The DTC(s) can be cleared by using the scan tool.

Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation.

Check for a poor connection or damaged ECM/TCM harness. Inspect the serial data link circuit for the following conditions:
- Improper mating
- Broken locks
- Improperly formed
- Damaged terminals
- Poor terminal-to-wire connection
- Damaged harness

Steps 1 - 5:

DTC P0700 Transmission Control System Malfunction