P1397

DTC P1397

Circuit Description

The engine control module (ECM) determines linear wheel speed fail threshold. The ECM detects a good or failed wheel speed sensor under power conditions.

Conditions for Setting the DTC

* The wheel speed variation test detects at least one missing edge from the wheel speed sensor signal.

* DTCs P0106, P0107, P0108, P0115, P0116, P0117, P0118, P0122, P0123, P0126, P0201, P0202, P0203, P0204, P0217, P0300, P0351, P0352, P0402, P0404, P0405, P0406, and P1404 are not set.

* Coolant temperature is greater than or equal to 60°C (140°F).

* The ignition voltage is between 11-16 volts.

* The engine is running.

Action Taken When the DTC Sets

* The malfunction indicator lamp (MIL) will not illuminate.

* The ECM will store conditions which were present when the diagnostic trouble code (DTC) set as failure records data only. This information will not be stored as freeze frame data.

* A history DTC is stored.

Conditions for Clearing the MIL/DTC

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

* The DTCs can be cleared by using the scan tool.

* Disconnecting the ECM battery feed for more than 10 seconds.

Diagnostic Aids

Inspect for the following conditions:

* Poor connection at the ECM-Inspect the harness connections for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.

* Damaged harness-Inspect the wiring harness for damage. If the harness appears to be OK, observe the G sensor display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the fault.

An open pulse width modulation (PWM) serial data line between the ECM and the electronic brake control module (EBCM) will cause this DTC to set.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1.

The diagnostic system check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.

6.

The replacement ECM must be reprogrammed. Refer to the latest Techline procedure for ECM reprogramming.