Pinpoint Test I: Traction Control Indicator on the Switch is Always Illuminated

WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Lighting Control Module for schematic and connector information.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Vehicle Dynamic Systems for schematic and connector information.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Instrument Cluster for schematic and connector information.

Normal Operation

The ABS module sends a reference voltage to the traction control switch along circuit 959 (GY) to the traction control switch. When the switch is pressed, the reference voltage continues through the switch to ground along circuit 57 (BK). The ABS module then disables the traction control system when it detects this change in reference voltage and sends a message to the instrument cluster along the high-speed controller area network (HS-CAN) bus to illuminate the indicator. After receiving the ABS module message, the instrument cluster sends a message to the lighting control module (LCM) along the serial communication protocol (SCP) bus to illuminate the indicator and the LCM supplies voltage to circuit 961 (WH/PK) which illuminates the indicator.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
LCM
Instrument cluster
ABS module

PINPOINT TEST I: TRACTION CONTROL INDICATOR ON THE SWITCH IS ALWAYS ILLUMINATED

I1 CHECK THE ABS MODULE FOR DTCs
- Connect the diagnostic tool.
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: Self-Test ABS
- Retrieve and record any ABS module DTCs.
- Are any DTCs retrieved?
1. YES : Go to the ABS Module DTC Index .
2. NO : Go to I2.
I2 CHECK THE LCM OUTPUT
- Key in OFF position.
- Disconnect: LCM C2145a
- Key in ON position.
- Does the traction control switch indicator continue to illuminate?
1. YES : REPAIR circuit 961 (WH/PK). TEST the system for normal operation.
2. NO : Go to I3.
I3 CHECK THE COMMUNICATION WITH THE LCM
- Key in OFF position.
- Connect: LCM C2145a
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: DataLogger LCM
- Using the scan tool, check the communication with the LCM.
- Does the scan tool communicate with the LCM?
1. YES : Go to I4.
2. NO : REFER to MODULE COMMUNICATIONS NETWORK article to diagnose the no communication concern.
I4 CHECK THE COMMUNICATION WITH THE INSTRUMENT CLUSTER
- Enter the following diagnostic mode on the diagnostic tool: DataLogger Instrument Cluster
- Using the scan tool, check the communication with the instrument cluster.
- Does the scan tool communicate with the instrument cluster?
1. YES : Go to I5.
2. NO : REFER to MODULE COMMUNICATIONS NETWORK article to diagnose the no communication concern.
I5 CHECK THE ABS TRACTION CONTROL SYSTEM PID (TCYC_FS)
- Enter the following diagnostic mode on the diagnostic tool: DataLogger ABS
- Check the state of the TCYC_FS PID.
- Does the PID display ACTIVE?
1. YES : INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation.
2. NO : Go to I6.
I6 CHECK FOR CORRECT LCM OPERATION
- Key in OFF position.
- Disconnect: LCM C2145a
- Disconnect: LCM C2145b
- Check the connectors for:
  - corrosion.
  - pushed-out pins.
  - spread terminals.
- Connect: LCM C2145a
- Connect: LCM C2145b
- Make sure the connectors are seated correctly, then operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new LCM. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.
2. NO : Go to I7.
I7 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect: Instrument Cluster C220
- Check the connector for:
  - corrosion.
  - pushed-out pins.
  - spread terminals.
- Connect: Instrument Cluster C220
- Make sure the connector is seated correctly, then operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new instrument cluster. REFER to INSTRUMENTATION, MESSAGE CENTER, & WARNING CHIMES article. TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.