Code
DF987
RENAULT
D
-> P0575 - Keys cruise control / speed limiter
AI status
Completed
Completed
100%
Causes
- Faulty cruise control / speed limiter switch stalk or steering-wheel button unit
- Damaged wiring harness, chafed wires or poor connector contact
- Blown fuse or poor power/ground to the switch/module
- Faulty brake or clutch pedal switch (interlock) preventing cruise enable
- CAN/bus communication error or module failure (BCM, ECM, instrument cluster)
- Water ingress or corrosion in switch or connectors
Symptoms
- Cruise control and/or speed limiter do not engage
- Cruise control indicator lamp not illuminating or blinking
- Related warning or message on dash (e.g., cruise unavailable)
- DTC DF987 / P0575 stored in one or more control modules
- Intermittent operation of cruise/speed limiter functions
What to check
- Scan all modules, read DTCs and freeze-frame data; note when code sets and any related codes
- Visually inspect fuses and relays related to cruise/BCM and replace if blown
- Inspect connectors and wiring for the steering wheel stalk, BCM and instrument cluster for damage or corrosion
- Check operation of brake and clutch pedal switches (they must open/close correctly)
- Monitor live data: confirm switch inputs or CAN messages are present when keys/buttons are pressed
- Wiggle test wiring/connectors while monitoring live data to detect intermittent faults
Signal parameters
- Steering-wheel/stalk switch: expected change in logic state when pressed (open/closed) — typically 0V/12V or a low-voltage logic level depending on design; refer to service manual for exact levels
- Brake/clutch switch: closed when pedal released (or as vehicle-specific) — continuity should change with pedal movement
- CAN bus: two-wire differential pair with approx. 2.5 V idle each line (nominal differential ~0 V with bias) and normal message traffic when vehicle awake; absence of expected steering button messages indicates communication fault
- Resistance values: switch/stalk continuity should be stable (manufacturer specification required for exact ohms)
- No diagnostic error frames or high error counts on CAN when the system is tested
Diagnostic algorithm
- Read and log all stored codes from all modules. Note related communication or input faults.
- Attempt to reproduce the fault (operate cruise keys and speed limiter) while watching live data for switch state and CAN messages.
- Inspect fuses, grounds and connectors for the steering-wheel control, BCM and instrument cluster. Repair any visual damage.
- Test brake and clutch pedal switches for proper operation and adjustment; replace if out of spec.
- Check continuity between the switch unit and the receiving module connector. Repair or replace wiring/connector if open/short/intermittent.
- If the switch is resistive or multiplexed, test the stalk/switch module according to the manufacturer's procedure (bench test if removed).
- Probe CAN lines with a scanner/oscilloscope to confirm message presence and bus integrity; repair bus faults if present.
- If wiring and switches are good, suspect BCM/module fault — check for software updates or reflashing procedure before replacing the module.
- After any repair, clear codes and retest function in road test to confirm the fault is resolved.
Likely causes
- Failed steering-wheel switch/stalk assembly
- Connector corrosion or broken wire in harness to switch or BCM
- Brake/clutch switch misadjusted or defective
- Loss of CAN messages from the switch/module to BCM/ECM
- Blown fuse or missing ground to the control circuit
Fault status
Status
DF987 (P0575) — Cruise control / speed limiter keys input fault: switch or communication circuit not recognised. Check steering wheel/stalk, brake/clutch interlock switches, wiring/connectors and CAN/bus communications.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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