C1240

Symptoms

• The ABS indicator on the dashboard is on
• ABS does not activate when braking
• Possible activation of other related systems (ESP, EBD)
• Error C1240 saved in logbook

Causes

• Damage to the wiring harness to the differential pressure sensor
• Short circuit in the sensor circuit
• Malfunction of the differential pressure sensor itself
• Corrosion or oxidation of contacts
• Problems with the ABS hydraulic unit

How to Fix

1. Carry out diagnostics with a scanner to confirm the code
2. Visually inspect the wiring harness and sensor contacts
3. Check the resistance and voltage in the sensor circuit
4. If necessary, replace the sensor or repair the wiring harness
5. Clean or replace corroded contacts
6. In difficult cases, replace the ABS hydraulic unit

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