A011

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
This DTC checks the state of the ABS indicator lamp to identify a situation in which the driver could not be warned of a system malfunction by the ABS indicator lamp, or the indicator lamp is always "ON." The Lamp Driver Module (LDM) turns the ABS indicator lamp "ON," unless the Electronic Brake Control Module (EBCM) provides ground to turn it "OFF." Because of the circuitry in the LDM, only external malfunctions can be detected. As a result, the ABS indicator lamp itself is not diagnosable, only the control line to the EBCM can be diagnosed. In the event of an open CKT 852, the ABS indicator lamp will be "ON" at all times, due to the loss of ground at the LDM input. If the control line is shorted to ground, the ABS indicator lamp is kept "OFF," due to the LDM input being grounded.

FAILURE CONDITION
DTC A011 can be set only during the three second bulb check or when the ABS indicator lamp is commanded "ON." If the EBCM cannot control the ABS indicator lamp for two seconds, a malfunction exists.

ACTION TAKEN
A malfunction DTC is stored; however, ABS is not disabled.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks to see if ABS lamp functions properly. Normal operation would indicate that the problem is not present.
2. This step determines if any other DTCs are present or if A018 is set falsely.
3. This step insures that the circuitry from the EBCM to the lamp driver module is complete.
4. This step insures that the ignition circuit to the lamp driver module is functional. An open indicator fuse or open CKT 3, 39, or 875 would result in inoperative indicator lamp.
5. Isolates the cause of the ABS lamp remaining "OFF," by disconnecting the 24-way EBCM connector, CKT 852 should be open and cause the ABS lamp to be "ON."
6. This step determines whether the lamp remains "ON" due to a lamp driver malfunction or an open in CKT 852.
7. Determines if the "INDIC" fuse or CKT 3 is open, causing the I/P indicator lamps to remain "OFF."
8. This step checks for an open in CKT 39 which supplies voltage to the lamp driver module.
9. Isolates the cause of the lamp remaining "OFF" to a short to ground in CKT 852 or a malfunctioning lamp driver module.

DIAGNOSTIC AIDS
An "Intermittent" malfunction may be caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.

The lamp test function of the Tech 1 may be used to command the lamp "ON" while looking for an intermittent malfunction in the ABS indicator lamp circuitry.

The frequency of the malfunction can be checked by using the enhanced diagnostic function of the Tech 1.

Any circuitry that is suspected as 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.