Volvo Diagnostics Overview

Overview






The transmission control module (TCM) (1) has on-board diagnostics (Volvo On-board Diagnostic system) which continuously monitors the TCM input and output signals. A fault in the system will result in the TCM storing a Diagnostic Trouble Code (DTC) and the warning lamp in the combined instrument (3) will begin flashing. (There are exceptions however, refer to the table D. Diagnostic Codes.) Information on possible faults and other information as well can be read off from the system in the following ways:

Volvo diagnostics: By reading off the output from the Data Link Connector (DLC) (2).

OBD II: Using a fault-tracing instrument attached to the OBD II socket (6) on the bracket in front of the gear shift (only certain markets, USA and Canada).


Volvo diagnostics:

Communication with the system is via the Data Link Connector (DLC) A1. Information can be displayed in three ways:

- Flashing LED combinations and pressing buttons on the DLC (2)
- Volvo Scan Tool (Diagnostic Key) (5)
- Volvo Scan Tool (System Tester) (4) with cassette memory for text readouts (only certain markets, USA and Canada)

Using Volvo Diagnostics the following Diagnostic Test Modes (DTMs) can be utilized:

DTM 1: Display and erase stored Diagnostic Trouble Codes (DTC)
DTM 2: Receive confirmation that certain system components are operating.
DTM 3: Activate system components following a routine of tests.
DTM 4: Activate the same components as in DTM 3 but activation takes place component by component, as requested by the operator.

DTM 5: Continuous readings from certain sensors in the system.
DTM 6: Enter information in the transmission's control system.