Iveco 113 – Engine Control Unit (ECU) / EDC: Mismatch signal switches the brake pedal and acceleration sensors

The control module is receiving conflicting data indicating that both the brake pedal and the accelerator pedal are being pressed at the same time. This is typically caused by a stuck brake light switch or an accelerator pedal position sensor (APPS) sending a high-voltage signal while brakes are applied, resulting in the vehicle cutting power, limiting torque, or entering limp mode.

• Iveco Daily
• Iveco Stralis
• Iveco Eurocargo
• Iveco Tector
• Irisbus
• Iveco Bus

1. 1

   Perform a visual and mechanical inspection of the brake and accelerator pedals to ensure neither is binding, sticking, or failing to return to its resting position due to a broken return spring or debris.

2. 2

   Observe the vehicle's brake lights. If they remain illuminated when the pedal is not being pressed, the brake light switch is likely stuck, misadjusted, or internally shorted.

3. 3

   Connect an OBD diagnostic scanner to the EDC and monitor the Brake Switch State. It should read 'OFF' at rest and 'ON' when depressed.

4. 4

   Monitor the Accelerator Pedal Position (APP1/APP2) voltages via the scanner. Slowly press the accelerator pedal; the voltage should sweep smoothly (typically between ~0.5V and 4.5V) without any dropouts or erratic spikes.

5. 5

   Inspect the wiring harnesses and connectors at both the brake pedal switch and the accelerator pedal. Look for corrosion, bent pins, water ingress, or chafed wires that could cause a short to ground or power.

1. 1

   Disconnect Power

   Disconnect the negative battery terminal to prevent electrical shorts and to prepare the EDC for a reset.

2. 2

   Replace the Brake Light Switch

   Locate the brake light switch mounted on the bracket above the brake pedal arm. Unplug the electrical connector, remove the switch (usually by twisting 90 degrees counterclockwise and pulling out), insert the new OEM brake switch, and twist it into place. Ensure the plunger is properly adjusted so the pedal arm fully depresses it when at rest.

3. 3

   Replace the Accelerator Pedal Assembly

   If the throttle sensor is the issue, unplug the electrical connector at the top of the pedal assembly, remove the mounting bolts securing it to the floor or bulkhead, install the new pedal assembly, torque the bolts to factory spec, and reconnect the wiring harness.

4. 4

   Reassembly and Clearing Codes

   Reconnect the battery and use a diagnostic scanner to clear the 0113 fault code from the EDC memory.

5. 5

   Road Test

   Test drive the vehicle to ensure the MIL/Injector warning light stays off, brake lights operate normally, and throttle response is restored without triggering limp mode.