Diagnostic trouble code (DTC) information

WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.

Condition

Fig 1: Identifying Idle Air Control (IAC) Valve

Courtesy of VOLVO CARS OF NORTH AMERICA.

Diagnostic trouble code (DTC) ECM-8A is stored if there is a short-circuit to supply voltage in the idle air control (IAC) valve signal cable or if there is an open-circuit in the circuit that the control module interprets as a fault.

Substitute Value

The conditions for fuel shut-off are changed.

Possible Source

Signal too high:

Short-circuit to supply voltage in the signal cable
Faulty idle air control (IAC) valve.

Signal too low:

Short-circuit to ground in the signal cable
Faulty idle air control (IAC) valve.

Signal missing:

Open-circuit in the signal cable:
Faulty idle air control (IAC) valve.

Fault symptom[s]

High idling speed
Low idling speed
Malfunction indicator lamp (MIL) lit.