Using The Volvo 440 Diagnostic System

 

The Volvo 440 dates back to an era where Car manufacturers were actually helpful (or at least some of them were), and as a result has a built in Diagnostic system. No going to the Garage to have fault codes read, so long as you know how to use the system.

This article tells you exactly how to do just that!

Under the bonnet, just above the airbox should be a little black box with a white connector in it. Simply lift the top of this box up to open the Diag system. You should see an LED, a button and 7 holes (each numbered).

We'll discuss what each of these holes is in a minute, but let's get the important first steps down first so that you don't risk blowing your ECU!

 

Pre-Requisites

 

  • Ignition MUST be OFF before attempting to insert the connector. This is incredibly important if you don't want to risk damaging anything. The only exception being the Cruise-Control checks

That was simple, so let's look at what each of the holes does. We select a function by simply inserting the white connector into the relevant hole

1 Alarm and Remote Lock
2 Fuel System
3 ABS
4 Unknown
5 Unknown
6 Cruise Control
7 Airbag

 

So now we know what most of the holes do, we need to look at how to actually use the system.

 

Reading Codes

 

  1. Ensure the ignition is OFF
  2. Insert the Diagnostic Connector in the appropriate hole
  3. Turn the ignition ON to position II (I.e. don't start the engine).
  4. Wait 10-20 seconds
  5. Press the button and hold for 2 seconds
  6. The LED will flash out the codes (see below), with a three second pause between each section of the fault code. You need to count each flash to identify the codes. If it flashes 1-1-1 then no codes are stored
  7. Record the code (pen and paper required!)
  8. Press the button and hold for 2 seconds to move onto the next code (if there are no other codes it will flash the same code again)
  9. Repeat until all codes are recorded
  10. Switch Ignition OFF and remove the connector from the hole.

 

 

Resetting Codes

 

  1. Same process as above, but leave the ignition on
  2. Press and hold the button for more than 5 seconds
  3. The LED will light up, press and hold the button for more than 5 seconds again
  4. When the LED switches off the codes have been cleared
  5. Read the codes again and you should only receive 1-1-1

 

Note: Certain systems (especially the ABS) will, when codes are reset, illuminate a dashboard warning lamp. This will switch off during a test-drive (for ABS once you pass 15MPH).

 

 

Notes

When an issue is suspected, it's always wise to read the codes, erase them and then read them again after a test-drive (where possible). It also needs to be said that if a sensor is reported as faulty, this is not always actually the case. If you are detecting multiple sensor failures, look for common ground. It may be a sign of a blown fuse, damaged cabling or anything in between. In short, always consider the probability of that sensor being damaged against the probability of something that sensor depends on being damaged!

For example, when checking ABS, if you get any code in the 1-5-x range it's more likely that the wiring to that sensor has been damaged than the sensor itself.

 

 

Keyfob Programming

Whilst not strictly a diagnostic function, the diagnostic unit is also used when programming new remotes into the alarm system. To do so, follow the steps below. The car will allow you to program up to 4 remotes.

 

  1. Ignition OFF
  2. Connect the diagnostic connector to hole 1
  3. Lock and unlock the car using the existing (i.e. already recognised) remote
  4. Switch Ignition ON
  5. Press button on diagnostic unit 4 times
  6. LED should come on
  7. Press button 3 time, then 4 times, then 4 times again
  8. Press unlock button on the first remote to be programmed
  9. Repeat for each additional remote

 

 

Fault Codes

Alarm and Remote Locking (Hole 1)

Code Description
1-1-1 No error detected
1-1-3 Weak Signal: Transmitter to Receiver (Usually dying battery in KeyFob)
1-1-4 Faulty Control module
2-1-1 Relay, fuse or control terminal (locking)
2-1-2 Relay, fuse or control terminal (unlocking)
2-2-1 Fuse or Ground Terminal (locking)
2-2-2 Fuse or Ground Terminal (unlocking)
2-2-3 Both of the above combined
3-1-2 Internal fault on siren
3-2-1 Power supply to Siren
4-1-2 Motion Detection System: Internal Fault
4-1-3 Motion Detection System: 1 or more sensors Faulty
5-1-1 Key switch ground on (> 10 Seconds)
5-1-2 Key switch ground off (>10 Seconds)
5-1-3 Locking Door with ignition on
5-1-4 Unlocking Door with ignition on
5-2-1 Central locking system switch (>10 Seconds Locked)
5-2-2 Ultrasonic switch (>20 seconds locked)
5-3-1 Interior lights shorting to ground

 

Fuel System (Hole 2)

Code Description
1-1-1 No error detected
1-1-2 Malfunction in ECM
1-1-3 Open circuit in Injector Wiring
1-2-1 Air Pressure sensor not responding
1-2-3 Coolant temp sensor not responding
1-3-2 Incorrect battery voltage
1-4-3 Knock Sensor: Not responding or faulty
2-1-2 Oxygen Sensor: Not responding or faulty
2-1-4 Flywheel Sensor: Not Responding or faulty
2-2-2 System relay coil: no voltage
2-2-3 Idle Speed Valve: Not responding or faulty
2-3-1 Lambda closed loop system lean or rich under part-load
2-3-2 Lambda closed loop system lean or rich at idle
2-4-4 Knock Sensor: Not Responding or faulty
3-1-1 Speedometer Sensor: Not Responding or faulty
3-1-3 Charcoal Absorption Can Valve Faulty
3-4-2 A/C relay: Signal Faulty
3-4-3 Main Relay Coil: No Voltage
4-1-1 Throttle Valve Sensor: Not Responding or faulty

 

ABS (Hole 3)

Code Description
1-1-1 No error detected
1-2-1 Left Front Sensor: Faulty signal at less than 25mph
1-2-2 Right Front Sensor: Faulty signal at less than 25mph
1-2-3 Left Rear Sensor: Faulty signal at less than 25mph
1-2-4 Right Rear Sensor: Faulty signal at less than 25mph
1-2-5 Faulty signal from >= 1 sensor for long period
1-3-5 Faulty Control module
1-4-1 Pedal Sensor faulty
1-4-2 Faulty Brake lamp switch (open circuit)
1-4-4 Brake Discs overheated
1-5-1 Left Front Sensor: Open Circuit
1-5-2 Right Front Sensor: Open Circuit
1-5-5 Rear Axle sensor: Open Circuit
2-1-1 Left Front Sensor: No Signal when moving off
2-1-2 Right Front Sensor: No Signal when moving off
2-1-3 Left Rear Sensor: No Signal when moving off
2-1-4 Right Rear Sensor: No Signal when moving off
2-1-5 Valve Relay: Open or short circuit
2-2-1 Left Front Sensor: ABS Operation Signal missing
2-2-2 Right Front Sensor: ABS Operation Signal missing
2-2-3 Left Rear Sensor: ABS Operation Signal missing
2-2-4 Right Rear Sensor: ABS Operation Signal missing
2-3-1 Left Front Sensor: Signal Missing
2-3-2 Right Front Sensor: Signal Missing
2-3-5 Rear Axle Sensor: Signal Missing
3-1-1 Left Front Sensor: Open or short Circuit
3-1-2 Right Front Sensor: Open or short Circuit
3-1-3 Left Rear Sensor: Open or short Circuit
3-1-4 Right Rear Sensor: Open or short Circuit
3-2-1 Left Front Sensor: Irregular interference at > 25MPH
3-2-2 Right Front Sensor: Irregular interference at > 25MPH
3-2-3 Left Rear Sensor: Irregular interference at > 25MPH
3-2-4 Right Rear Sensor: Irregular interference at > 25MPH
4-1-1 Left front inlet valve: Open or short circuit
4-1-2 Left front Return valve: Open or short circuit
4-1-3 Right front inlet valve: Open or short circuit
4-1-4 Right front Return valve: Open or short circuit
4-1-5 Rear valve: Open or short circuit
4-2-1 Rear inlet valve: Open or short circuit
4-2-2 Rear return valve: Open or short circuit
4-2-3 Traction Control valve: Open or short circuit
4-2-4 TRACS pressure switch: Faulty or short circuit
4-4-1 Control module Faulty
4-4-2 Pump Pressure Low
4-4-3 Pump Motor/Relay Fault
4-4-4 No power to valves in hydraulic unit

 

Cruise Control (Hole 6)

You will not be able to retrieve any of these codes unless you leave the ignition ON after a test drive. Codes are not stored to non-volatile memory.

Code Description
1-1-1 No error detected
1-1-2 Vehicle Speed Sensor: Abnormal Signal
1-2-2 Vehicle Speed not exceeded 25MPH or no signal
2-1-1 Fault in power supply or control module
2-1-2 Vacuum pump or regulator signal faulty

 

Airbag/SRS (Hole 7)

Code Description
1-1-1 No error detected
1-1-2 Internal fault in sensor unit
1-2-7 SRS Warning lamp: Open or short circuit
2-1-1 Steering wheel module: Short Circuit
2-1-2 Steering wheel module: Open Circuit
2-1-3 Steering wheel module: Ground leak
2-1-4 Steering wheel module: Short to Live
2-2-1 Passenger module: Short Circuit
2-2-2 Passenger module: Open Circuit
2-2-3 Passenger module: Ground leak
2-2-4 Passenger module: Short to Live
2-3-1 Left Belt tensioner: Short Circuit
2-3-2 Left Belt tensioner: Open Circuit
2-3-3 Left Belt tensioner: Ground Leak
2-3-4 Left Belt tensioner: Short to Live
2-4-1 Right Belt tensioner: Short Circuit
2-4-2 Left Belt tensioner: Open Circuit
2-4-3 Left Belt tensioner: Ground Leak
2-4-4 Left Belt tensioner: Short to Live