Volvo 850 2.3L Turbo (1994 – 1997) OBD1 Codes

Model:	850 2.3L Turbo
Year:	1994-97
Engine identification:	B5234T/T2/T3/T4/T6
System:	Bosch Motronic 4.4 Siemens Fenix 5.1

General information

Engine control module (ECM) incorporates self-diagnosis function.
Malfunction indicator lamp (MIL) will illuminate if certain faults are recorded.
ECM operates in backup mode if sensors fail, to enable vehicle to be driven to workshop.

Accessing and erasing

The engine control module (ECM) fault memory can only be accessed and erased using diagnostic equipment connected to the data link connector (DLC) 1.

Trouble code identification

Scan code	Fault location	Probable cause
EFI-0011	Heated oxygen sensor (H02S)	Wiring, H02S
EFI-0012	Mass air flow (MAF) sensor	Wiring, MAF sensor
EFI-0013	Intake air temperature (IAT) sensor	Wiring, IAT sensor
EFI-0014	Throttle position (TP) sensor	Wiring, TP sensor, lAC valve signal exceeded 2 V for 4 seconds
EFI-0021	Engine coolant temperature (ECT) sensor	Wiring, ECT sensor
EFI-0022	Crankshaft position (CKP) sensor/engine speed (RPM) sensor	Wiring, poor connection, CKP/RPM sensor
EFI-0023	Camshaft position (CMP) sensor	Wiring, poor connection, CMP sensor
EFI-0024	Speedometer	Wiring, speedometer
EFI-0025	Barometric pressure (BARO) sensor	Wiring, BARO sensor
EFI-0031	Knock sensor (KS)	Wiring, KS
EFI-0036	Engine control module (ECM) – ignition adjustment signal	Activation of ignition adjustment incomplete
EFI-0041	Injectors	Wiring, injector(s), injector control moduiEl
EFI-0044	Ignition coil	Spark plug(s), wiring, ignition coil
EFI-0054	Immobilizer control module – communication error	Wiring
EFI-0056	Fuel pressure sensor	Wiring, fuel pressure sensor
EFI-0058	Fuel trim (FT) – abnormal intake air volume	Wiring, lAC valve, intake air by-pass valve
EFI-0064	Alternator	Wiring, alternator
EFI-0066	Brake vacuum sensor	Wiring, brake vacuum sensor
EFI-0089	Fuel trim (FT) – high/low	Intake leak/blockage, fuel pressure/pump, wiring, IAT sensor, BARO sensor, MAF sensor
EFI-112	Engine control module (ECM)	ECM
EFI-115	Injector 1	Wiring, injector
EFI-116	Engine control module (ECM)- internal fault	ECM
EFI-121	Mass air flow (MAF) sensor/manifold absolute pressure (MAP) sensor	Intake leak/blockage, hose leak, wiring, MAF/MAP sensor
EFI-122	Intake air temperature (IAT) sensor	Wiring, IAT sensor
EFI-123	Engine coolant temperature (ECT) sensor	Wiring, ECT sensor
EFI-125	Injector 2	Wiring, injector
EFI-131	Crankshaft position (CKP) sensor/engine speed (RPM) sensor – no signal	Wiring, CKP/RPM sensor
EFI-132	Engine control module (ECM) – supply voltage	Battery, alternator, wiring
EFI-137	Crankshaft position (CKP) sensor/engine speed (RPM) sensor	Wiring, flywheel/drive plate damaged, CKP/RPM sensor insecure/defective
EFI-135	Injector 3	Wiring, injector
EFI-143	Knock sensor (KS) 1	Wiring, KS
EFI-145	Injector 4	Wiring, injector
EFI-153	Heated oxygen sensor (H02S) 2	Exhaust leak, wiring, H02S 1/2
EFI-155	Injector 5	Wiring, injector
EFI-165	Injector 6	Wiring, injector
EFI-211	Mixture adjustment resistor	Wiring, mixture adjustment resistor incorrectly adjusted/defective
EFI-212	Heated oxygen sensor (H02S) 1	Wiring, H02S 1/2
EFI-214	Crankshaft position (CKP) sensor/engine speed (RPM) sensor- incorrecUintermittent signal	Poor connection, shield wiring, flywheel/drive plate damaged, CKP/RPM sensor
EFI-216	Heated oxygen sensor (H02S)	Wiring, H02S
EFI-222	Engine control relay	Wiring, engine control relay
EFI-223	Idle air control (lAC) valve – opening signal	Wiring, lAC valve
EFI-225	AJC refrigerant pressure sensor	Wiring, AJC refrigerant pressure sensor
EFI-226	Idle air control (lAC) valve	Wiring, lAC valve
EFI-227	Idle speed control (ISC) valve	Wiring, ISC valve
EFI-231	Long term fuel trim, part load	Intake/exhaust leak, fuel pressure, excessive fuel in engine oil, engine oil level too high, injector(s), EVAP canister purge valve, wiring, MAF sensor, ECT sensor, H02S
EFI-232	Long term fuel trim, idling	Intake/exhaust leak, fuel pressure, excessive fuel in engine oil, engine oil level too high, injector(s), EVAP canister purge valve, wiring, MAF sensor, ECT sensor, H02S
EFI-233	Long term fuel trim, idle air adjustment	Intake leak/blockage, throttle valve adjustment, accelerator cable adjustment, wiring, lAC valve
EFI-235	Exhaust gas recirculation (EGR) solenoid	Wiring, EGR solenoid
EFI-242	Turbocharger (TC) wastegate regulating valve	Wiring, TC wastegate regulating valve
EFI-245	Idle air control (lAC) valve – closing signal	Wiring, lAC valve
EFI-251	Outside air temperature sensor	Wiring, outside air temperature sensor
EFI-254	Engine control relay	Wiring, engine control relay
EFI-311	Vehicle speed signal	Wiring, speedometer
EFI-314	Camshaft position (CMP) sensor	Wiring, poor connection, CMP sensor
EFI-315	Evaporative emission (EVAP) canister purge valve – leak detected	EVAP canister purge valve
EFI-323	Malfunction indicator lamp (MIL)	Wiring, MIL
EFI-325	Engine control module (ECM) – memory fault	ECM disconnected, battery discharged/ disconnected, wiring
EFI-335	Transmission control module (TCM) – MIL ON request	Wiring
EFI-336	Transmission control module (TCM) – gear recognition	Wiring
EFI-337	Transmission control module (TCM)/traction control module – torque reduction signal	Wiring, TCM, traction control module
EFI-338	Engine control module (ECM) – immobilizer authorisation signal missing	Immobilizer trouble code IMM-322 stored, wiring
EFI-342	AJC relay	Wiring, AIC relay
EFI-343	Fuel pump relay	Wiring, fuel pump relay
EFI-353	Immobilizer control module – communication error	Wiring, poor connection, immobilizer control module
EFI-355	Mass air flow (MAF) sensor – incorrect signal	MAF sensor, TP sensor
EFI-411	Throttle position (TP) sensor	Wiring, TP sensor
EFI-414	Turbocharger (TC) boost pressure – control	Hose blocked, TCM wire (TC pressure reduction signal), wiring, MAF sensor, TC wastegate actuator/regulating valve
EFI-415	Manifold absolute pressure (MAP) sensor, TC system	Wiring, MAP sensor, BARO sensor
EFI-422	Barometric pressure (BARO) sensor	Wiring, sensor supply, BARO sensor, AIC pressure sensor, fuel tank pressure sensor, G-force sensor
EFI-425	Heated oxygen sensor (H02S) 2	Intake/exhaust leak, uneven compression, fuel pressure, H02S
EFI-432	Engine control module (ECM) – overheating	Engine coolant blower motor, air supply blocked
EFI-433	Knock sensor (KS) 2	Wiring, KS
EFI-435	Heated oxygen sensor (H02S) 1 – slow response	Intake/exhaust leak, uneven compression, fuel pressure, MAF sensor, heating inoperative, H02S
EFI-436	Heated oxygen sensor (H02S) 2 – compensation	Intake/exhaust leak, uneven compression, fuel pressure, H02S 1/2
EFI-442	Pulsed secondary air injection (PAIR) system – excessive flow detected	PAIR valve/solenoid, exhaust leak
EFI-443	Catalytic converter – efficiency below threshold	Intake/exhaust leak, uneven compression, fuel pressure, catalytic converter
EFI-444	G-force sensor	Wiring, sensor supply, A/C pressure sensor, fuel tank pressure sensor, G-force sensor
EFI-445	Pulsed secondary air injection (PAIR) pump relay	Wiring, PAIR pump relay
EFI-446	Pulsed secondary air injection (PAIR) valve – leak detected	PAIR valve/solenoid, exhaust leak
EFI-447	Pulsed secondary air injection (PAIR) solenoid	Wiring, PAIR solenoid
EFI-448	Pulsed secondary air injection (PAIR) system – incorrect flow detected	PAIR valve/solenoid, PAIR pump/relay, hoses/pipes blocked, exhaust leak, PAIR pump wiring
EFI-451	Cylinder 1 – misfire detected	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-452	Cylinder 2 – misfire detected	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-453	Cylinder 3 – misfire detected	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-454	Cylinder 4 – misfire detected	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-455	Cylinder 5 – misfire detected	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-456	Cylinder 6 – misfire detected	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-512	Short term fuel trim	Intake/exhaust leak/blockage, MAF sensor, fuel pressure
EFI-513	Engine control module (ECM) – overheating	Engine coolant blower motor, air supply blocked
EFI-514	Engine coolant blower motor relay, low speed	Wiring, engine coolant blower motor relay
EFI-515	Engine coolant blower motor relay, high speed	Wiring, engine coolant blower motor relay
EFI-516	A/C condenser blower motor relay	Wiring, A/C condenser blower motor relay
EFI-521	Heated oxygen sensor (H02S) 1 – heater control	Wiring, H02S
EFI-522	Heated oxygen sensor (H02S) 2 – heater control	Wiring, H02S
EFI-525	Ignition coil 1, cylinders 1 & 4	Wiring, ignition coil
EFI-526	Ignition coil 2, cylinders 2 & 3	Wiring, ignition coil
EFI-532	Engine control module (ECM) – power stage – group B	Wiring, lAC valve, TC wastegate regulating valve, engine coolant blower motor relay, ECM
EFI-533	Engine control module (ECM) – power stage – group C	Wiring short circuit at terminal 819, ECM
EFI-534	Engine control module (ECM) – power stage – group D	Wiring short to positive, MIL, engine coolant blower motor relay, fuel pump, ignition coil/ amplifier, TCM (load signal), ECM
EFI-535	Engine control module (ECM) – power stage – groupE	Wiring short to positive, AJC relay/PAIR pump relay, ECM
EFI-541	Evaporative emission (EVAP) canister purge valve – signal	Wiring, EVAP canister purge valve
EFI-543	Misfire detected, at least 1 cylinder	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-545	Misfire detected – at least 1 cylinder – TWC damage	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-551	Cylinder 1, misfire detected – TWC damage	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-552	Cylinder 2, misfire detected- TWC damage	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-553	Cylinder 3, misfire detected – TWC damage	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-554	Cylinder 4, misfire detected – TWC damage	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-555	Cylinder 5, misfire detected – TWC damage	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-556	Cylinder 6, misfire detected – TWC damage	Spark plug, HT lead, distributor rotor/cap, moisture ingress, injector/wiring, air leak, compression, head gasket, low-tension wiring, repeated cold starts (flooding)
EFI-611	Fuel tank system – large leak detected	Fuel tank, filler cap/pipe, EVAP system, fuel tank pressure sensor
EFI-612	Fuel tank system – small leak detected	Fuel tank, filler cap/pipe, EVAP system, fuel tank pressure sensor
EFI-614	Evaporative emission (EVAP) canister shut-off valve – incorrect flow detected	Hose blocked, EVAP canister shut-off valve/ filter, EVAP canister purge valve, fuel tank pressure sensor
EFI-616	Evaporative emission (EVAP) canister shut-off valve – signal	Wiring, EVAP canister shut-off valve
EFI-621	Fuel tank pressure sensor	Wiring, sensor supply, G-force sensor, A/C pressure sensor, fuel tank pressure sensor
EFI-666	Transmission control module (TCM) – access fault memory	Trouble code(s) stored
EFI-724	Engine coolant heater relay	Wiring, engine coolant heater relay, engine coolant heater wiring
EFI-725	Engine control relay	Wiring, engine control relay
EFI-726	Engine control module (ECM) – supply voltage	Wiring, engine control relay
EFI-730	Brake pedal position (BPP) switch	Brake pedal depressed for more than 3 minutes, wiring, BPP switch
EFI-732	Accelerator pedal position (APP) sensor – signal	Wiring, APP sensor
EFI-733	Accelerator pedal position (APP) sensor – supply voltage	Wiring short to ground, excessive load, ECM
EFI-742	Transmission control module (TCM) – communication error	Wiring, TCM, ECM
EFI-743	Cruise control master/selector switch	Wiring, cruise control master/selector switch