Code
C0042
Generic
C — Chassis
Brake Pedal Position Sensor Circuit A
Views:
UK: 17
EN: 45
RU: 25
AI status
Completed
Completed
100%
Causes
- Open or short in BPP sensor A wiring (broken conductor, chafed insulation)
- Corroded, loose, or damaged connector at the sensor or module
- Failed BPP sensor (potentiometer, Hall-effect, or switch type)
- Short to battery voltage or short to ground on the signal or reference circuits
- Poor ground or low reference voltage from the vehicle control module
- Contamination or mechanical binding at the pedal sensor (dirt, moisture, deformation)
Symptoms
- ABS/ESC or brake warning lamp illuminated
- Cruise control disabled or inoperative
- Brake lights may be stuck ON or OFF (if integrated switch issue)
- Reduced or altered brake/vehicle control behavior, possible limp/reduced functionality of related systems
- Diagnostic trouble codes stored for brake pedal/switch circuits
What to check
- Retrieve freeze frame and full DTC list with a scan tool; record live BPP sensor data
- Visually inspect wiring and connector at the brake pedal sensor for damage, corrosion, bent pins, or contamination
- Backprobe the sensor connector and check for reference voltage (typically ~5V) and good ground with ignition on
- Measure BPP sensor signal voltage with pedal at rest and while slowly depressing the pedal (expect a smooth, monotonic change for analog sensors)
- Check for continuity between sensor connector and the module connector; check for shorts to battery and ground
- Wiggle test harness while watching live data for intermittent changes
Signal parameters
- Reference voltage: typically ~5.0 V (confirm factory spec)
- Signal voltage (analog potentiometer/Hall): typically ~0.5–4.5 V across pedal travel (at rest near one end, at full press near the other)
- Signal behavior: smooth, monotonic change with pedal travel (no jumps, dropouts, or stuck values)
- Switch-type: logical states of ~0 V (ground) or battery voltage (~12 V) depending on design
- Short indications: signal pegged at 0 V (short to ground) or ~battery voltage (short to Vb)
Diagnostic algorithm
- Park vehicle on level ground, set parking brake, key off. Follow vehicle-specific safety procedures.
- Connect a scan tool and confirm C0042 plus any related codes; note live BPP signal value and stored conditions.
- Visually inspect the BPP sensor and wiring harness near the pedal for mechanical damage, chafing, or contamination; repair obvious damage.
- With ignition ON (engine off), backprobe the sensor connector: verify reference voltage (≈5V) and good ground at the connector.
- Measure the sensor signal voltage at rest and while slowly depressing the pedal. Expect a smooth change (≈0.5–4.5V) for analog types. If signal is stuck, erratic, or pegged, suspect wiring or sensor.
- If reference or ground missing, trace and test continuity back to the vehicle control module; repair open or poor connection.
- Check for short to battery or ground: disconnect sensor and measure resistance from signal pin to ground and battery; low resistance to either indicates short.
- Perform a wiggle test (move harness and pedal) while monitoring live data to find intermittent faults. Repair or replace harness/connector if intermittent occurs.
- If wiring and connectors test good, replace the BPP sensor and recheck signal and codes.
- Clear codes and road-test to confirm repair. If C0042 returns, consider module input fault and consult manufacturer tech data before replacing module.
Likely causes
- Damaged or chafed wiring harness near the brake pedal
- Corroded/poor connector at the sensor or splice
- Failed sensor (internal wear or water ingress)
- Loss of 5V reference or poor ground at the sensor
Fault status
Status
C0042 — Brake Pedal Position Sensor Circuit A: signal out of range (open/short/intermittent).
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
Similar codes
Workshop Manuals
Available brands with manuals
2
AUDI 11
6-speed manual gearbox 0B1, front-wheel drive — Workshop Manual (Edition 05.2014)
Workshop ManualAudi A3 (1997) – 1.6L 4-cylinder (2‑valve) Engine Mechanical Components Service Manual (AEH, AKL, APF) – Edition 07.2002
Workshop ManualAUDI A3 (2004) Workshop Manual — 2.0L FSI Turbo (4‑cyl, 4‑valve) Engine, Mechanics — Edition 03.2017
Workshop ManualAudi A3 2004 — Electrical System (Workshop Manual, Edition 02.2018)
Workshop ManualAudi A4 / A4 Cabriolet – 4.2 l V8 (5‑valve, timing chains) – Workshop Manual (Mechanics) – Edition 04.2007
Workshop ManualAudi A4 / A4 Cabriolet — Auxiliary Heater Workshop Manual (Edition 08.2004)
Workshop ManualAudi A4 / A4 Cabriolet (1.8T 4‑cyl turbo) — Motronic Injection & Ignition System Service Manual (Edition 01.2015)
Workshop ManualAudi A8 (2003) — Electrical System Workshop Manual (Edition 08.2014)
Workshop ManualAudi Q4 e-tron (Type F4) - Self-study Programme SSP 685
Workshop ManualAudi Q8 (2018) — Electrical System Workshop Manual (Edition 05.2019)
Workshop ManualAudi Servicing Manual — 7‑Speed Dual Clutch Transmission 0CJ / 0CL / 0CK / 0DN / 0DP / 0HL (Edition 05.2018)
Workshop ManualLAND ROVER 3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop ManualLand Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop ManualLand Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop ManualYour experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
C0042
HYUNDAI
C — Chassis
Brake Pedal Position Sensor “Circuit A” (Subfault)
Views:
UK: 21
EN: 32
RU: 14
AI status
Completed
Completed
100%
Causes
- Open or short in BPP sensor A wiring (broken conductor, chafed insulation)
- Corroded, loose, or damaged connector at the sensor or module
- Failed BPP sensor (potentiometer, Hall-effect, or switch type)
- Short to battery voltage or short to ground on the signal or reference circuits
- Poor ground or low reference voltage from the vehicle control module
- Contamination or mechanical binding at the pedal sensor (dirt, moisture, deformation)
Symptoms
- ABS/ESC or brake warning lamp illuminated
- Cruise control disabled or inoperative
- Brake lights may be stuck ON or OFF (if integrated switch issue)
- Reduced or altered brake/vehicle control behavior, possible limp/reduced functionality of related systems
- Diagnostic trouble codes stored for brake pedal/switch circuits
What to check
- Retrieve freeze frame and full DTC list with a scan tool; record live BPP sensor data
- Visually inspect wiring and connector at the brake pedal sensor for damage, corrosion, bent pins, or contamination
- Backprobe the sensor connector and check for reference voltage (typically ~5V) and good ground with ignition on
- Measure BPP sensor signal voltage with pedal at rest and while slowly depressing the pedal (expect a smooth, monotonic change for analog sensors)
- Check for continuity between sensor connector and the module connector; check for shorts to battery and ground
- Wiggle test harness while watching live data for intermittent changes
Signal parameters
- Reference voltage: typically ~5.0 V (confirm factory spec)
- Signal voltage (analog potentiometer/Hall): typically ~0.5–4.5 V across pedal travel (at rest near one end, at full press near the other)
- Signal behavior: smooth, monotonic change with pedal travel (no jumps, dropouts, or stuck values)
- Switch-type: logical states of ~0 V (ground) or battery voltage (~12 V) depending on design
- Short indications: signal pegged at 0 V (short to ground) or ~battery voltage (short to Vb)
Diagnostic algorithm
- Park vehicle on level ground, set parking brake, key off. Follow vehicle-specific safety procedures.
- Connect a scan tool and confirm C0042 plus any related codes; note live BPP signal value and stored conditions.
- Visually inspect the BPP sensor and wiring harness near the pedal for mechanical damage, chafing, or contamination; repair obvious damage.
- With ignition ON (engine off), backprobe the sensor connector: verify reference voltage (≈5V) and good ground at the connector.
- Measure the sensor signal voltage at rest and while slowly depressing the pedal. Expect a smooth change (≈0.5–4.5V) for analog types. If signal is stuck, erratic, or pegged, suspect wiring or sensor.
- If reference or ground missing, trace and test continuity back to the vehicle control module; repair open or poor connection.
- Check for short to battery or ground: disconnect sensor and measure resistance from signal pin to ground and battery; low resistance to either indicates short.
- Perform a wiggle test (move harness and pedal) while monitoring live data to find intermittent faults. Repair or replace harness/connector if intermittent occurs.
- If wiring and connectors test good, replace the BPP sensor and recheck signal and codes.
- Clear codes and road-test to confirm repair. If C0042 returns, consider module input fault and consult manufacturer tech data before replacing module.
Likely causes
- Damaged or chafed wiring harness near the brake pedal
- Corroded/poor connector at the sensor or splice
- Failed sensor (internal wear or water ingress)
- Loss of 5V reference or poor ground at the sensor
Fault status
Status
C0042 — Brake Pedal Position Sensor Circuit A: signal out of range (open/short/intermittent).
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email