U1113

Code

DS U — Network/User

Fault in communication with the ABS/ESP ECU on the CAN: No signal

Brand: DS

Type: U — Network/User

Views: UK: 1 EN: 2 RU: 6

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Page language: EN

Causes

ABS/ESP ECU unpowered (blown fuse, relay fault, connector disengaged)
Open or short in CAN-H or CAN-L wiring (broken wire, chafing, corrosion)
Poor ground at ABS/ESP ECU or gateway module
Failed ABS/ESP ECU or gateway/module hardware
Missing or failed CAN termination resistor(s)
Low battery voltage or intermittent power supply

Symptoms

ABS warning lamp illuminated
ESP/traction control warning lamp illuminated
Loss of ABS, ESP and traction control functions
Cruise control or stability systems disabled
Instrument cluster displays communication warning or error message
No live ABS/ESP data available on diagnostic scanner

What to check

Retrieve freeze frame data and all stored U/C/P codes with a capable scan tool
Attempt to communicate with ABS/ESP ECU using a diagnostic tool (check for response and message IDs)
Check battery voltage and charging system (nominal 12–14.5 V)
Inspect fuses and relays related to ABS/ESP power and gateway modules
Visually inspect ABS/ESP ECU connector for corrosion, bent pins, water ingress, or damage
Perform wiggle test on ABS wiring harness and connectors while monitoring CAN traffic

Signal parameters

Idle single-ended voltages: CAN-H ≈ 2.5 V, CAN-L ≈ 2.5 V
Differential voltage when transmitting: CAN-H ≈ 3.5–4.0 V, CAN-L ≈ 1.0–1.5 V (approx differential 2.0–3.0 V)
Termination resistance: ≈ 60 ohms measured between CAN-H and CAN-L (two 120 Ω in parallel typical)
Common CAN data rates: 500 kbps or 250 kbps (confirm vehicle-specific rate)
Expected ABS/ESP message IDs: vehicle-specific — confirm with factory data or OEM scan tool
Bus idle current: near 0 mA except wake-up or active transmission (use scope/current clamp for intermittent faults)

Diagnostic algorithm

Connect a full-function OEM or capable diagnostic scanner. Record all U-codes and related modules reporting faults.
Attempt bi-directional communication with ABS/ESP ECU. Note if module responds or times out.
Verify battery voltage and charging system; ensure stable supply (>12 V) during diagnostics.
Check fuses/relays supplying ABS/ESP ECU and gateway; restore if blown and re-test.
Visually inspect ABS ECU connector and harness for corrosion, water damage, or mechanical damage; repair any issues found.
With ignition ON, measure CAN-H and CAN-L voltages at the ABS/ESP ECU connector and at the gateway—confirm ~2.5 V idle and correct differential when active.
If no differential signal, measure resistance between CAN-H and CAN-L at two network points to confirm ~60 Ω termination. Look for open or short to ground/power.
Use an oscilloscope to view CAN waveforms while stimulating the network (crank, ABS operation, or module scan). Look for missing or corrupted frames.
Isolate segments: disconnect suspected modules (after safe procedures) or unplug branch connectors to find the fault location. Re-check bus activity after each isolation.
Inspect/repair any wiring faults found (repair broken conductors, clean/replace corroded connectors, secure grounds).
If wiring and terminations are good and the ABS ECU still does not respond, swap or bench-test the ABS/ESP ECU if possible or consult OEM for module reprogramming/replacement.
Clear codes, road-test and re-scan. If fault returns, escalate to module-level diagnostics or manufacturer support.

Likely causes

Fuse or power supply to ABS/ESP ECU blown or disconnected
Broken or high-resistance CAN bus conductor between ABS ECU and gateway
Faulty ABS/ESP ECU (internal failure)
Missing/failed termination resistor causing no differential signaling
Gateway/module not forwarding CAN messages (gateway failure)
Corrosion or loose connector at ABS/ESP ECU causing loss of signal

Fault status

⚠️ Status

No CAN communication received from ABS/ESP ECU (timeout/no signal). The ABS/ESP module is not transmitting or the CAN network is not delivering its messages.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 2.0-4.0 hours

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