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Home / DTC / C1A71 — Manufacturer-specific control module fault (C1A71)

C1A71 — Manufacturer-specific control module fault (C1A71)

Detailed page for trouble code C1A71.

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C1A71

LAND ROVER C — Chassis

Manufacturer-specific control module fault (C1A71)

Brand: LAND ROVER
Type: C — Chassis
Views: UK: 3 EN: 7 RU: 7
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Page language: EN

Causes

  • Intermittent or failed control module hardware (CPU, memory, internal sensors)
  • Corrupted or incompatible module software/calibration
  • Loss of power or ground to the control module
  • Poor connector contacts, damaged wiring or chafing
  • CAN/LIN or other network communication errors or bus faults
  • Recent module replacement, programming, or network topology change

Symptoms

  • Related system warning light(s) illuminated (may be generic or system-specific)
  • Affected system inoperative or intermittent operation (e.g., body, infotainment, powertrain subsystem depending on module)
  • Multiple communication-related DTCs present (lost messages, invalid data)
  • Key-on self-test failures or programming errors after module replacement

What to check

  • Read all stored DTCs and freeze-frame data from all modules, not only the module that reported C1A71
  • Check for additional network/can bus U-codes and related manufacturer codes
  • Visually inspect module connectors and harness for corrosion, bent pins, water ingress, and damage
  • Verify module supply voltage and ground at the connector (key ON and cranking if applicable)
  • Confirm recent service history: module replacement, reflash, software updates or battery disconnects
  • Scan for pending codes and clear then re-test to see if fault returns

Signal parameters

  • Module supply voltage (V) at harness pin — key ON and engine running where applicable
  • Module ground resistance to chassis (Ω) or voltage drop under load
  • CAN bus differential voltage (V_CANH/V_CANL) and idle bus voltage
  • Bus error counters or message loss rates (if available on scanner)
  • Module internal self-test status or fault counters (if provided)
  • Freeze-frame parameters: ignition state, battery voltage, network traffic snapshot

Diagnostic algorithm

  1. Retrieve DTCs from all control modules using a dealer-level or manufacturer-capable scanner; save reports. 2) Note any related network codes (U-codes) and address them first — fix wiring/terminals on CAN/LIN if present. 3) Perform a visual inspection of the suspect module and harness for damage, moisture, or loose/corroded pins. 4) With a multimeter, verify battery voltage at the module connector (should be close to battery voltage with key ON); check ground for low resistance/voltage drop. 5) Use a scope or capable scan tool to observe CAN/LIN signals for noise, missing frames, or abnormal voltages. 6) If power/ground and bus are good, confirm module software/part/calibration numbers against manufacturer data; update or reprogram only with correct file if required. 7) If programming fails repeatedly or intermittent internal faults persist, consider module replacement per manufacturer procedure. 8) After any repair or reprogram, clear codes and perform full system tests and a road test to verify the fault does not return. Document findings and steps taken.
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Likely causes

  • Faulty control module internal electronics
  • Low or intermittent module supply voltage or poor ground
  • Corroded connector or broken pin at the module harness
  • CAN bus short to battery or ground causing communication errors
  • Incomplete or failed software reflash or incorrect calibration file

Fault status

⚠️ Status
Manufacturer-specific control module fault stored (C1A71). The control module reports an internal or operational error; refer to manufacturer repair procedures for detailed diagnostics and reprogramming requirements.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1-3 hours

Similar codes

C1A70 C1A72 U0100 U0401 P0606
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