Code
P0569
GWM
P — Powertrain
- Cruise control system brake signal malfunction
AI status
Completed
Completed
100%
Causes
- Faulty or misadjusted brake light / brake pedal switch
- Open, shorted or corroded wiring or connector between brake switch and BCM/ECM
- Blown fuse or bad relay in the cruise/brake input circuit
- Poor ground or low battery/voltage supply to modules
- Body Control Module (BCM) or Engine/TCU input circuit fault
- Aftermarket electrical work or trailer harness interfering with brake circuit
Symptoms
- Cruise control will not engage or disables immediately
- Cruise/system warning on instrument panel
- Brake lights may not work correctly (stay on, not light, or intermittent)
- Related systems (ABS, traction) may show faults if shared wiring
- Stored DTC P0569 (brake signal malfunction) and possibly other brake-input codes
What to check
- Scan for P0569 and any other stored or pending codes, view freeze-frame and live data
- Visually inspect brake light switch, pedal mounting and switch adjustment
- Check brake lights operation while actuating pedal
- Inspect wiring harness and connectors for corrosion, damage, or aftermarket taps
- Check relevant fuses and power/ground at BCM and cruise module
- Backprobe brake switch and module connector to confirm signal presence with pedal operation
Signal parameters
- Brake-switch typical states: open (no pedal) and closed (pedal pressed). Expect 0 V vs battery depending on circuit polarity or approx. battery voltage (~12–14 V) in the active state
- Closed-switch continuity: near 0 ohms between switch terminals (spec varies by design)
- When available, live-data should show brake input status toggling consistently with pedal operation (no intermittent dropouts)
- No high-frequency modulation expected — signal is a steady switched state in most GWM systems
Diagnostic algorithm
- Retrieve all codes and freeze-frame; note any companion codes (ABS/BCM/communication).
- Inspect brake pedal switch for correct mounting and adjustment; verify brake lights operate when pedal pressed.
- Check relevant fuse(s) and power/ground to the brake switch and BCM. Repair any blown fuses or bad grounds.
- Backprobe the brake switch harness while operating the pedal. Confirm the switch toggles between expected voltages and has good continuity when closed.
- Backprobe the brake input at the BCM/cruise module connector to confirm the signal is reaching the module. Compare voltages to the switch end to isolate harness fault.
- If signal is present at the switch but not at the module, inspect/repair wiring between the two (look for chafing, corrosion, or aftermarket splices).
- If signal is correct at module input but DTC persists, check module power/grounds and CAN/communication lines; perform module self-test procedures per service manual.
- If available, replace brake switch with known-good unit (or swap BCM where allowed) to confirm component failure. Clear codes and road-test to verify repair.
- Consult vehicle wiring diagrams and manufacturer service information before replacing modules. Record test results and re-scan after each repair step.
Likely causes
- Failed or out-of-adjustment brake light / pedal switch (most common)
- Connector corrosion or loose pin at brake switch or BCM
- Damaged wiring (chafing, pinched, short to ground or +12V) along harness
- Blown fuse or poor power/ground to BCM
- BCM or cruise control module internal fault (less common)
Fault status
Status
Brake signal input to cruise control detected as faulty or missing. Cruise functionality disabled until brake input circuit is repaired or verified.
Repair difficulty: Medium
Diagnostic time: 0.8-2.5 hours
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