Pinpoint Test N: The Brake Warning Indicator Is Always On
- Refer to Wiring Diagrams INSTRUMENT CLUSTER
for schematic and connector information.
Normal Operation and Fault Conditions
See Brake Warning Indicator, ABS/Brake/Stability-Traction Control System Indication and Brake Fluid Level Switch. REFER to: Instrument Panel Cluster (IPC) - System Operation and Component Description .
If the brake fluid level warning, brake (red) warning indicator request or parking brake warning indicator request messages are missing or invalid for less than 5 seconds, the IPC defaults the brake warning indicator to the last indication mode (on/off) based upon the last message received.
If the brake fluid level warning, brake (red) warning indicator request or parking brake warning indicator request messages are missing or invalid for 5 seconds or longer, the IPC defaults the brake warning indicator on.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition BCM B1048:01 Brake Fluid Level Switch: General Electrical Failure A continuous and on-demand DTC that sets in the BCM when the BCM detects an open on the brake fluid level switch input. BCM B1048:7B Brake Fluid Level Switch: Low Fluid Level A continuous and on-demand DTC that sets in the BCM when the BCM detects low brake fluid level. BCM C1D00:11 Park Brake Apply Switch: Circuit Short To Ground A continuous and on-demand DTC that sets in the BCM when the BCM detects the parking brake applied or a short to ground on the parking brake input. Possible Sources
- Wiring, terminals or connectors
- Brake fluid level switch
- Parking brake system concern
- Electric park brake (if equipped)
- ABS concern
- GWM
- BCM
- IPC
Visual Inspection and Pre-checks
- Inspect the base brake system and the parking brake system for correct operation.
- Inspect the brake fluid level switch connection and check for signs of connector terminal damage, corrosion or pushed-out pins.
- Inspect the brake fluid level switch wiring for signs of a cut or opened circuit.
- Inspect the brake fluid level switch for signs of any external damage.
- N1 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE IPC (INSTRUMENT PANEL CLUSTER) SELF-TEST
- Ignition ON.
- Using a diagnostic scan tool, perform the IPC self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to DTC Chart: IPC in Diagnostic Trouble Code (DTC) Chart . No GO to N2 - N2 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE BCM (BODY CONTROL MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the BCM self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes For DTC B1048:01, GO to N7 For DTC B1048:7B, VERIFY the brake fluid level is low. If the brake fluid is low, CORRECT the low brake fluid condition. REFER to the appropriate Service Information. If the brake fluid is not low, INSTALL a new brake fluid level switch. For DTC C1D00:11 (manual parking brake), GO to N5 For all other Diagnostic Trouble Codes (DTCs), REFER to: Body Control Module (BCM) . No GO to N3 - N3 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: Communications Network . No GO to N4 - N4 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE SELF-TEST
- Using a diagnostic scan tool, perform the ABS module self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to the Master DTC Chart. No For manual parking brake, GO to N5 For electric park brake, REFER to Parking Brake . - N5 CHECK THE PARKING BRAKE SWITCH
- Ignition OFF.
- Disconnect Parking Brake Switch C306.
- Ignition ON.
- Using a diagnostic scan tool, view the BCM Parameter Identifications (PIDs).
- Access the BCM and monitor the PARK_BRK_SW PID
- Monitor the parking brake PID with the parking brake released.
Does the PID indicate the parking brake is released?
Yes INSTALL a new parking brake position switch. No GO to N6 - N6 CHECK THE PARKING BRAKE SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect BCM C2280E.
- Measure:
Positive Lead Measurement / Action Negative Lead C2280E-47 Ground
Is the resistance greater than 10, 000 ohms?
Yes GO to N12 No REPAIR the circuit. - N7 CHECK THE BRAKE FLUID LEVEL SWITCH INPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect BCM C2280F.
- Ignition ON.
- Measure:
Lead 1 Measurement / Action Lead 2 C2280F-28 Ground
Is any voltage present?
Yes REPAIR the circuit. No GO to N8 - N8 CHECK THE BRAKE FLUID LEVEL SWITCH INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect Brake Fluid Level Switch C124.
Is the resistance less than 3 ohms?
Yes GO to N9 No REPAIR the circuit. - N9 CHECK THE BRAKE FLUID LEVEL SWITCH GROUND CIRCUIT FOR AN OPEN
- Measure:
Positive Lead Measurement / Action Negative Lead C124-2 Ground
Is the resistance less than 3 ohms?
Yes GO to N10 No REPAIR the circuit. - Measure:
- N10 CHECK THE BRAKE FLUID LEVEL SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure:
Positive Lead Measurement / Action Negative Lead C2280F-28 Ground
Is the resistance less than 3 ohms?
Yes GO to N11 No GO to N12 - N11 CHECK THE BRAKE FLUID LEVEL SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND WITH THE BRAKE FLUID LEVEL SWITCH DISCONNECTED
Is the resistance greater than 10, 000 ohms?
Yes INSTALL a new brake fluid level switch. No REPAIR the circuit. - N12 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all BCM 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 BCM 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 BCM. Refer to Body Control Module (BCM) . 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.