DTC 48

Diagnostic Trouble Code No. 48 - Secondary Air Injection System Malfunction





CIRCUIT DESCRIPTION
The ECM drives an electric air pump to send air into the exhaust system and remove CO and HC from the engine exhaust gases by oxidation.

When the engine is cold-started, the ECM activates the electric air pump relay to drive the air pump. And because the BSB is also turned on at this time, the intake manifold pressure opens the air switching valve (ASV) to start secondary air injection.

Within a few minutes of secondary air injection starting, the ECM turns off the air pump relay and VSV when the engine condition reaches a predetermined level, thus stopping secondary air injection.

Code 48 Description:

DETECTING CONDITION

Code 48 Diagnostic Chart:

DIAGNOSTIC CHART

Code 48 Circuit Diagram:

WIRING DIAGRAM

Code 48 Inspection Procedure:

INSPECTION PROCEDURE