If codes other than these are indicated, repeat self-diagnosis. If codes reappear, substitute a known good ECM, and recheck codes.

If you have no idea how to pull codes, see the quick'n'nasty instructions below.

The Fenix 5.2 system is used on the 10 valve non turbocharged 850
The Motronic 4.3 system is used on the 20 valve turbocharged and some non-turbo'ed 20 valve B5254 S engines
The Bosch LH 3.2 Jetronic system is used on the 20 valve non-turbocharged except some B5254 S engines using Motronic.
 

   Note that the following codes are a compilation of descriptions from a number of sources. 
   It has been the compilation 'policy' to err on the side of too much information rather than too little. 
   Interpretation/Discretion is your responsibility.

CODE	Fenix 5.2 System  PROBABLE CAUSE for Volvo vehicles
1-1-1	No faults
1-1-2	ECU faulty
1-1-3	Fuel injectors; From 1994 and later, Heated oxygen sensor - maximum enrichment sensed short term fuel mixture too weak
1-1-5	Injector no. 1 cylinder faulty signal
1-2-1	Manifold Absolute Pressure (MAP) signal absent or faulty
1-2-2	Air Temperature sensor signal absent or faulty
1-2-3	Coolant temperature sensor signal absent or faulty
1-2-5	Injector no. 2 cylinder faulty signal
1-3-1	Ignition System RPM signal
1-3-2	Battery voltage too low/high
1-3-3	Throttle switch signal (idle)
1-3-5	Injector no. 3 falty signal
1-4-2	ECU faulty
1-4-3	(front) knock sensor signal missing or sensor defective
1-4-4	Fuel system load signal (missing or defective)
1-4-5	Injector no. 4 cylinder faulty signal
1-5-2	air pump valve signal absent or faulty (only on some emission controlled vehicles)
1-5-3	Rear heated oxygen sensor signal
1-5-4	EGR system - leakage or excessive flow
1-5-5	Injector no. 5 cylinder faulty signal
2-1-2	heated oxygen Sensor Signal (front sensor on 1994 and later models) absent or faulty
2-1-3	Throttle switch signal (wide-open)
2-1-4	Ignition rpm sensor signal erratic, absent or faulty
2-2-1	Lambda Operation; also Heated oxygen sensor (mixture too rich under part throttle) / long term fuel mixture too weak in part load stage
2-2-2	Main relay signal absent or faulty
2-2-3	Idle air control valve signal absent or faulty
2-2-4	Coolant temperature sensor signal
2-2-5	A/C pressure sensor signal absent or faulty
2-3-1	Lambda adjustment; For 1994 and later, heated oxygen sensor (mixture too lean under part throttle) / long term fuel mixture too rich in part load stage
2-3-2	Lambda adjustment; For 1994 and later, adaptive heated oxygen sensor control / long term fuel mixture too weak at idle
2-3-3	Idle valve - closed or intake air leak / long term idle air trim outside control range
2-3-4	Throttle switch signal missing
2-4-1	EGR malfunction
2-4-5	Idle air control valve - closing signal
3-1-1	Speedometer signal
3-1-2	Knock/Fuel enrichment signal missing
3-1-4	Camshft position sensor signal missing or defective
3-1-5	EVAP emission control system
3-2-1	Cold start valve - signal missing
3-2-2	Airflow meter hot wire
3-2-4	Camshaft position sensor signal erratic
3-2-5	ECU memory failure
3-3-5	TCM request for MIL (CHECK ENGINE light)
4-1-1	Throttle switch signal faulty or missing
4-1-3	EGR temperature sensor signal incorrect or missing
4-1-4	Turbo boost regulation
4-1-6	Turbo boost reduction from TCM
4-2-5	Temperature warning level no. 1
4-3-1	EGR temperature sensor faulty or missing
4-3-2	High temperature warning inside ECU
4-3-3	No rear knock sensor signal
4-3-5	Front heated oxygen sensor - slow response
4-3-6	Rear heated oxygen sensor compensation
4-4-3	Catalytic converter efficiency
4-4-4	Acceleration sensor signal
4-5-1	Misfire cylinder no. 1
4-5-2	Misfire cylinder no. 2
4-5-3	Misfire cylinder no. 3
4-5-4	Misfire cylinder no. 4
4-5-5	Misfire cylinder no. 5
5-1-1	Adaptive oxygen sensor control, provides leaner mixture at idle
5-1-2	Oxygen intergrator at maximum lean running limit
5-1-3	High temperature warning inside ECU
5-1-4	Engine cooling fan - low speed signal faulty
5-2-1	Oxygen sensor preheating front
5-2-2	Oxygen sensor preheating rear
5-3-1	Power stage - group A
5-3-2	Power stage - group B
5-3-3	Power stage - group C
5-3-4	Power stage - group D
5-3-5	TC control valve signal
5-4-1	EVAP valve signal
5-4-2	Misfire on more than one cylinder
5-4-3	Misfire on at least one cylinder
5-4-4	Misfire on more than one cylinder, catalyic converter damage
5-4-5	Misfire on at least one cylinder, catalyic converter damage
5-5-1	Misfire on cylinder no. 1, catalyic converter damage
5-5-2	Misfire on cylinder no. 2, catalyic converter damage
5-5-3	Misfire on cylinder no. 3, catalyic converter damage
5-5-4	Misfire on cylinder no. 4, catalyic converter damage
5-5-5	Misfire on cylinder no. 5, catalyic converter damage

CODE	Motronic 4.3 System PROBABLE CAUSE for Volvo vehicles
1-1-2	ECU faulty
1-1-5	Injector no. 1 cylinder faulty signal
1-2-1	MAF signal absent or faulty
1-2-3	Coolant temperature sensor signal absent or faulty
1-2-5	Injector no. 2 cylinder faulty signal
1-3-1	Ignition System RPM signal absent or faulty
1-3-2	Battery voltage too low/high
1-3-5	Injector no. 3 faulty signal
1-4-3	(front) knock sensor signal missing or sensor defective
1-4-4	Fuel system load signal (missing or defective)
1-4-5	Injector no. 4 cylinder faulty signal
1-5-2	air pump valve signal absent or faulty (on certain engines)
1-5-4	EGR system - leakage or excessive flow (on certain engines)
1-5-5	Injector no. 5 cylinder faulty signal
2-1-2	heated oxygen Sensor Signal absent or faulty
2-1-4	Ignition rpm sensor signal intermittently absent
2-2-3	Idle air control valve signal absent or faulty
2-2-5	A/C pressure sensor signal absent or faulty
2-3-1	Long term fuel mixture too lean or rich in part load stage
2-3-2	long term fuel mixture too lean or rich at idle
2-3-3	long term idle air trim outside control range
2-3-5	EGR controller signal absent/faulty (on certain engines)
2-4-1	EGR flow fault (on certain engines)
2-4-3	throttle position sensor signal voltage incorrect (out of range)
2-4-4	knock control at limit
2-4-5	Idle air control valve closing signal faulty/absent
3-1-1	Speedo signal missing
3-1-3	EVAP valve signal absent/faulty (on certain engines)
3-1-4	Camshft position sensor signal missing or defective
3-1-5	EVAP emission control system fault (on certain engines)
3-2-3	Malfunction indicator lamp signal faulty
3-2-5	ECU memory failure
3-3-5	request for Malfunction indicator lamp signal from auto transmission ECU
3-4-2	airconditioning relay control signal fault
3-4-3	fuel pump relay control signal fault
4-1-1	Throttle position sensor signal not within correct voltage
4-1-3	EGR temperature sensor signal incorrect or missing (on certain engines)
4-1-4	Turbo boost pressure too high
4-1-6	Turbo boost reduction from auto transmission ECU(/TCM)
4-3-2	High temperature warning inside ECU
4-3-3	rear knock sensor signal absent/faulty
4-3-5	heated oxygen sensor - slow response
4-4-2	air pump relay signal absent/faulty (on certain engines)
5-1-1	long term fuel mix too rich @ idle
5-1-2	short term fuel mix too rich @ idle
5-1-3	High temperature warning inside ECU
5-1-4	Engine cooling fan at low speed faulty
5-1-5	Engine cooling fan at high speed faulty
5-2-1	Oxygen sensor heating fault
5-2-3	signal to ECU module box cooling fan shorted to 12 volts
5-2-4	fault in transmission torque control signal
5-3-5	turbo regulator valve fault
5-4-1	EVAP valve signal fault (on certain engines)

CODE

Bosch LH 3.2 Jetronic System PROBABLE CAUSE for Volvo vehicles

1-1-1 1-1-2 1-1-3 1-2-1 1-2-3 1-3-1 1-3-2 2-1-2 2-2-1 2-2-3 2-3-1 2-3-2 3-1-1 4-1-1 5-1-1 5-1-2

No faults ECU faulty short term fuel mixture too weak MAF signal absent or faulty Coolant temperature sensor signal absent or faulty Ignition System RPM signal absent or faulty Battery voltage too low/high heated oxygen Sensor Signal absent or faulty long term fuel mixture too weak in part load stage Idle air control valve signal absent or faulty Long term fuel mixture too lean or rich in part load stage Long term fuel mixture too lean at idle Speedo signal missing Throttle position sensor signal absent long term fuel mix too rich @ idle short term fuel mix too rich

 
 

Quick'n'nasty instructions

Gather Codes; Ignition off  Stick the flylead attached to the cover into A2 socket  Ignition on  press the button next to the led once  Codes appear as blinks, copy down the code onto paper.  Press button again after code displayed to see next code.  After all codes displayed, codes repeat.  (ie continue copying down codes until first code repeats.)  1-1-1 means nothing's there (hopefully, all OK).  Switch off ignition. Just because a code is there doesn't mean that it is a 100% certain problem for your car.  Electric spikes etc may occur giving false readings on the diagnostic system. Reset the system and then see if the error codes reappear. Fault codes can't be deleted until you have read them all at least once. Reset system; Ignition off  Stick the flylead attached to the cover into A2 socket  Ignition on  press the button next to the led once for about five seconds release red LED will light when lit, press the button next to the led again for about five seconds red LED goes out Ignition off, keep the flylead attached to the cover into A2 socket  Ignition on press button once for a second, ensure codes are cleared  or write down code(s) repeat code gathering procedure.