Volvo Fault Codes

Diagnostics

Several methods are used to read errors stored in Volvo control units:

• Self-diagnosis on the instrument cluster. With this method, a certain algorithm of actions is performed on the buttons of the panel, as a result of which fault codes appear on the screen.
• Diagnosis using a scanner and computer. In this case, you need a special adapter that connects to the connector in the machine and to a computer or other device. With the help of the program that must be downloaded from the Internet, error codes are read and decoded.
• The method common to the machines of the 90s is with the help of a self-test plug. A special connector is located in the engine compartment of cars in the area of the left wing (cars of release from 1985 to 1995). And it is a box in which an LED is installed, a test start button, a test mode selection cable and several connectors for connecting this cable. On the Volvo 960, 850 and 940 connector is located next to the air filter housing. From above, it is covered with a plastic casing. To perform a self-test, you must insert the cable into the socket and determine the errors by the number of flashes of the LED.

1985–1995 production machines

The code of the last diagnostic method has a three-digit format, with each digit being transmitted by the corresponding number of frequent flashes (1 - one, 3 - three, etc.). Between the groups are separated by a pause of three seconds. In the block there are two sections that allow you to receive fault codes of various nodes, each of which has six connectors.

Room / Section A / Section B

1 automatic transmission / Microclimate system (manual and automatic)

2 Fuel supply / Cruise control

3 ABS System / Reserve

4 TCU system on automatic transmission / Airbags and their control unit

5 Ignition system / Seat control

6 The health of the instrument panel / The health of the instrument cluster

To perform diagnostics, you must perform a standard test test:

1. Insert the cable into slot 2 of section A.
2. Switch on the ignition and briefly press the test start button.
3. If there is no error, the LED will discard code 111 (three short flashes at intervals of 3 seconds). If there is an error, it will be reported by other flash combinations.
4. Press the test button.

Testing is necessary before repeating the list of errors. The received codes need to be decrypted.

On release machines after 1996 

After 1996, a standard OBD-II diagnostic connector with 16 pins was installed on all Volvo cars. This connector is always located in the cabin near the console of the central tunnel or on the dashboard (on trucks). On the C70, V70 or S70 models of production until 1999 it is installed inside the armrest and closed with a removable plastic cover. On the Volvo 850 connector is located in front of the gearshift lever, and at 960 - to the side of the handbrake lever.

Diagnostics of such machines can be made according to a similar scheme described above, but using a separate diode, which is connected to pin 16 (positive pin) and 4. The device diagram is shown in the pictures below.

When conducting diagnostics and reading errors, it is necessary to take into account that there can be various control units on modern Volvo cars:

VSM - brake control system, including ABS and ESP systems;

SAS - tracking steering angle;

SRS - passive safety management (pillows and belts);

ECM - engine performance control;

AUM - audio system;

CEM - the central electronic control unit;

DIM - instrument cluster;

DDM - electronics in the driver's door;

CCM - microclimate system;

PDM - electronics in the front right door;

PSM - control of front seats and systems in them;

REM - electronic components of the back of the machine;

SWM - steering;

UEM - additional devices (alarm, sunroof, auto-dimming mirrors, etc.);

TCM - Transmission Control;

DEM - connection of a full drive (Haldex coupling unit).

If there are errors in any of the modules, for example, VSM, an inscription like “VSM DTC SET” will appear on the screen. If there is no error, the text will appear as “VSM Ready”. If a more in-depth analysis of the block is required, the words “SCM Checking” will appear on the combination.

 On modern Volvo FH12 or FH13 trucks, errors are displayed on the dashboard as text messages and burning symbols. For a more detailed error analysis on the block of the steering-wheel switches there are several keys with which you can go to the on-board computer menu and read the error code. This code is decoded according to the tables or reported when the truck is handed over for service.

Decoding codes

In total there are about a thousand different fault codes, typical for Volvo cars. Below will be considered the errors that are most often found on the machines.