104B01

What code 104B01 means

Code 104B01 points to a multiple fault in the intake manifold absolute pressure sensor (intake pipe). The sensor measures absolute intake air pressure, and the engine control unit (DME) uses its readings to calculate cylinder fill, manage fuel delivery, and control boost (where fitted).

A “Multiple fault” means the DME has logged several events tied to this sensor: for example, a signal outside the valid range, implausible readings, or an electrical fault in the circuit. The cause can be the sensor itself or the wiring (open circuit, short, corroded contacts).

Symptoms

• Rough running (fluctuating idle, hesitation, flat spots under acceleration).
• Check Engine light comes on.
• Possible loss of power (limp mode).

Symptoms may show up at idle, under load, or during transitions.

Diagnosis and repair

1. Read the fault codes with diagnostic equipment (ISTA, INPA) and check for related errors.
2. Check the absolute pressure sensor: inspect for damage or contamination, check the connector and the condition of the seals.
3. Check the wiring: continuity-test the circuit from the sensor to the DME, confirm there are no opens, shorts, or corroded contacts.
4. Replace the sensor with a known-good unit if needed.

After the repair, clear the codes and take a test drive to confirm the fault doesn't return.