Pinpoint Test U: The Brake Warning Indicator Or RTT (RECONFIGURABLE Telltale) Indicator Is Never On
- Refer to Wiring Diagrams INSTRUMENT CLUSTER
for schematic and connector information.
Normal Operation and Fault Conditions
See Brake Warning. REFER to: Instrument Panel Cluster (IPC) - System Operation and Component Description .
If the brake (red) warning indicator request or brake warning request messages are missing or invalid for less than 5 seconds, the IPC defaults the brake warning indicator to the last indication state (on or off), based upon the last message received.
Possible Sources
- Brake fluid level switch
- Parking brake system concern
- ABS concern
- GWM concern
- IPC
Visual Inspection and Pre-checks
- Inspect the brake fluid level switch for signs of any external damage.
- Inspect the wiring harness for signs of a pinched harness causing a shorted circuit.
- U1 IDENTIFY THE IPC (INSTRUMENT PANEL CLUSTER) LEVEL
- Determine if the vehicle is equipped with a 4-inch display IPC. REFER to: Instrument Panel Cluster (IPC) - Overview .
Is the vehicle is equipped with a 4-inch display IPC?
Yes GO to U3 No GO to U2 - U2 CHECK THE MESSAGE CENTER OPERATION
- Ignition ON.
- Close all doors and the hood.
- Clear all message center warnings by pressing the OK button for each warning present.
- Monitor the door ajar RTT warning indicator.
- Open the driver door.
- Clear the message center popup warning.
- Monitor the door ajar RTT warning indicator.
Is the door ajar RTT warning indicator off with the door closed, and on with the door open?
Yes GO to U4 No GO to Pinpoint Test A - U3 PERFORM THE IPC (INSTRUMENT PANEL CLUSTER) INDICATOR LAMP CONTROL ACTIVE COMMAND
- Ignition ON.
- Using a diagnostic scan tool, view the IPC Parameter Identifications (PIDs).
- Access the IPC and control the W_BRAKEPID
- Command the brake warning indicator on then off. Observe the brake warning indicator.
Does the brake warning indicator turn on when commanded on and turn off when commanded off?
Yes GO to U4 No GO to U9 - U4 CHECK THE BRAKE WARNING INDICATOR OPERATES WITH THE PARKING BRAKE APPLIED
- Apply the parking brake while monitoring the brake warning indicator.
Does the brake warning indicator illuminate?
Yes GO to U7 No GO to U5 - U5 CHECK THE PARKING BRAKE SYSTEM OPERATION
- Apply the parking brake.
Does the parking brake system apply the rear parking brakes?
Yes GO to U6 No REFER to: Parking Brake . - U6 CHECK THE GWM (GATEWAY MODULE A) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, check the GWM Continuous Memory Diagnostic Trouble Codes (CMDTCs).
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to: Controller Area Network (CAN) Module Communications Network . No DIAGNOSE the ABS. REFER to: Anti-Lock Brake System (ABS) and Stability Control . - U7 CHECK THE BRAKE FLUID LEVEL SWITCH OPERATION
- Ignition OFF.
- Disconnect Brake Fluid Level Switch C124.
- Ignition ON.
- Wait one minute.
Does the brake warning indicator illuminate?
Yes VERIFY the brake fluid level is low enough to turn on the brake warning indicator or has been reported low enough to turn on the brake warning indicator. If the brake fluid level is currently low or has been reported low, INSTALL a new brake fluid level switch. If the brake fluid level is not currently low or has not been reported low, the system is operating correctly at this time. No GO to U8 - U8 CHECK FOR CORRECT ABS (ANTI-LOCK BRAKE SYSTEM) MODULE OPERATION
- Ignition OFF.
- Disconnect and inspect the ABS module connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the ABS module connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM, or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new REFER to: Anti-Lock Brake System (ABS) Module . No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues. - U9 CHECK FOR CORRECT IPC (INSTRUMENT PANEL CLUSTER) OPERATION
- Ignition OFF.
- Disconnect and inspect the IPC connector.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the IPC connector. Make sure it seats and latches correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new IPC. REFER to: Instrument Panel Cluster (IPC) . No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.