Repair and service

GCU units are repaired, reflashed, recalibrated and tested by Apex Control Innovations. A unit that has stopped working is usually repairable, and the failures that occur are repeatable enough to be recognised.

Email contact@apex-control.com to start. That is the only intake route — there is no form and no portal.

What is serviceable

  • Firmware reflash, including a unit that no longer responds to the configuration software.
  • Board-level hardware repair — input and output stages, supplies, communication transceivers.
  • Input protection rework. The most common repair.
  • Recalibration after a repair, so the analog inputs read correctly again.
  • Full hardware test — every input, output and bus exercised against a known-good reference. Worth doing on a secondhand unit of unknown history before it goes into a car.

Common failure patterns

Named so you can recognise them, not so you can guess. A test is what confirms a diagnosis.

  • Damaged input protection, usually after a voltage transient — a jump start, a load dump, a solenoid or relay coil without a suppression diode, or a supply connected with reversed polarity. Symptom: one input reads a fixed or implausible value while the rest of the unit works normally.
  • Damaged output stages, usually after a short to ground or to battery positive on a solenoid circuit. Symptom: one output does nothing, or is permanently on.
  • Communication faults after a wiring fault on the bus. Symptom: no communication at all, or one bus dead while the other works.
  • Connector and harness damage. Frequently the actual fault when a unit is sent in as dead. Check the harness before shipping the unit.

Before sending anything, work through Faults and diagnostics — a good number of units arrive healthy, with the fault in the wiring.

The process

  1. Email the serial number, firmware version, transmission, vehicle and a description of the symptom.
  2. Shipping instructions come back, with what to include and what to leave out.
  3. Assessment. The unit is tested and the fault identified.
  4. Quote. You get the fault, the work needed and the price before anything is done. Nothing is repaired without your agreement.
  5. Repair and test. Every repaired unit is retested in full.
  6. Return, with a note of what was done.

Every repair is quoted case by case. There is no fixed price list, because what a unit needs varies. You will always see the price before any work starts.

What to send with the unit

The unit itself, the serial number, and a written description of the symptom and the vehicle context. Leave the harness attached only if the fault might be in it and you want it checked.

Where to go next