Initial Inspection and Diagnostic Overview

Accessory Electronic Module (AEM)

Diagnostic functions

General
The accessory electronic module (AEM) has a built-in diagnostic system, Volvo Diagnostic, which continuously monitors internal functions as well as input and output signals.

Diagnostic trouble codes (DTCs)
A diagnostic trouble code (DTC) is stored if the accessory electronic module (AEM) detects a fault. This control module can store up to 6 diagnostic trouble codes (DTCs), the 3 first and the 3 latest.

Should a fault disappear for any reason after being permanently stored in the control module as a diagnostic trouble code (DTC), the information remains stored in the memory.

Reading and erasing diagnostic trouble codes (DTCs)
Stored diagnostic trouble codes (DTCs) can be read off and erased using this function. The on-board diagnostic (OBD) system can identify 19 different faults in the accessory electronic module (AEM). These are stored as diagnostic trouble codes (DTCs).

This function can also be used to read off whether the fault is still present (permanent) or whether it has now ceased (intermittent) after the diagnostic trouble code (DTC) has been stored.

Diagnostic trouble codes (DTCs) can only be erased once all the diagnostic trouble codes (DTCs) have been read off at least once.

Reading off input and output signals
This function can be used to continuously read off the values and status of the accessory electronic module (AEM) input and output signals. The following parameters can be read off:
- power supply to the accessory electronic module (AEM)
- voltage level of the signal to the relay, engine block heater
- voltage level of alarm signals P0, P1, S0 and S1
- voltage level of the signal from tele-mute.

Activating components and functions
This function can be used to activate components and functions which affect the outputs of the accessory electronic module (AEM).

The following components can be activated:
- start signal to the electrical parking heater
- telemute signal which simulates the carphone muting the radio.

Reading off the control module identification
VIDA identifies control modules by reading off a number of codes from the control module memory.
The codes contain information about the control module:
- hardware P/N (control module without software)
- hardware serial number (control module without software)
- software P/N
- diagnostic software P/N
- start address CAN configuration.