Volvo 850 2.3L Turbo (1994 – 1997) Trouble Code Info

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

General information

  • Refer to the front of this manual for general test conditions, terminology, detailed descriptions of wiring faults and a general trouble shooter for electrical and mechanical faults.
  • 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