C1283

EBCM/PCM Schematic:

CIRCUIT DESCRIPTION
The Electronic Brake Control Module (EBCM) uses the Powertrain Control Module (PCM) to increase the engine idle speed during certain ABS events, especially those on icy road conditions.

The EBCM Is Connected To The PCM - through CKT 9YO1. When deemed necessary, the EBCM grounds this circuit which signals the PCM to increase idle speed from 850 rpm to 1500-2000 rpm. If an open or short to battery occurs in CKT 9YO1, the EBCM will be unable to request the PCM to increase engine speed. If a short to ground occurs in CKT 9YO1, the PCM will increase the engine idle speed continuously, once the vehicle speed has reached at least 20 km/h (12 mph).

CONDITIONS FOR SETTING THE DTC
This Diagnostic Trouble Code (DTC) will set when the following conditions are met:
^ This DTC can be set anytime after initialization for an open or short to ground in CKT 9YO1.
^ The EBCM can detect a short to voltage in CKT 9YO1 only during the time that the EBCM is requesting the PCM to idle-up.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS is not disabled and the ABS indicator lamp will not be illuminated.

CONDITIONS FOR CLEARING THE DTC
^ Conditions for the malfunction are no longer present and the Tech 2 scan tool Clear DTC Information function is used.
^ One hundred drive cycles have passed with no

DIAGNOSTIC AIDS
The frequency of the malfunction can be checked by using the Enhanced Diagnostic function of the Tech 2 scan tool, as described in Enhanced Diagnostics.

An Intermittent Malfunction - may be caused by a poor connection, rubbed through wire insulation or a wire that is broken inside the insulation. Any circuitry that is suspected of causing the intermittent complaint should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.

DTC C1283 Idle-Up Circuit Open Or Shorted To Voltage Or Ground (Part 1 Of 2):

DTC C1283 Idle-Up Circuit Open Or Shorted To Voltage Or Ground (Part 2 Of 2):

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
[2] Checks for a short to ground in CKT 9YO1.
[3] Checks for a short to voltage in CKT 9YO1.
[4] Checks for an open in CKT 9YO1.
[5] Tests the idle-up function with a Tech 2 scan tool.
[6] Checks the ability of the EBCM to ground CKT 9YO1 when commanding ON the idle-up function with a Tech 2 scan tool.