P1600

DTC P1600 Serial Communication Between ECM And TCM:

Serial Communication Between ECM And TCM:

CIRCUIT DESCRIPTION

The serial data circuit between the ECM and the TCM is pulled up to about 5 volts. The TCM transmits information to the ECM.


CONDITIONS FOR SETTING THE DTC


- No communication from the TCM for a specified time while the engine is running.


ACTION TAKEN WHEN THE DTC SETS


- The Malfunction Indicator Lamp (MIL) will illuminate.

- The ECM will record operating conditions at the time the diagnostic tails. This information will be stored in the Freeze Frame buffer.


CONDITIONS FOR CLEARING THE MIL/DTC


- The MIL will turn "OFF" after three consecutive drive cycles without a fault present.

- A DTC will clear after 40 consecutive warm-up cycles without a fault.

- DTC(s) can be cleared by using a scan tool or by disconnecting the ECM battery feed.

DIAGNOSTIC AIDS


Check for the following conditions:

- Poor connection or damaged harness. Inspect the wiring harness for damage.

If DTC P1600 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was last set. This may assist in determining how often the DTC sets.


If any wiring repairs need to be made, Refer to Repair Procedures in Diagrams.


TEST DESCRIPTION

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


1. The Engine OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

3. Reviews Freeze Frame data to determine when the DTC set. Always record this information