Suzuki >> Forenza 2.0L – Reno 2.0L – SX4 2.0L – Verona 2.5L (2004 – 2009)

Model Year Engine identification System
Forenza 2.0L 2004-08 U20SED   Suzuki EPI
Reno 2.0L 2005-08 U20SED   Suzuki EPI
SX4 2.0L 2007-09 J20A   Suzuki EPI
Verona  2.5L 2004-06 H25   Suzuki EPI

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.


  • Trouble codes can be displayed by using a Scan Tool connected to the data link connector (DLC):
o Forenza/RenoNerona – 1.
o SX4 1.


  • After the faults have been rectified, trouble codes can be erased by using a Scan Tool connected to the data link connector (DLC).

Trouble code identification

OBD·II code Fault location Probable cause
PO, P2, UO Refer to OBD-11 trouble code tables
P1106 Manifold absolute pressure (MAP) sensor – intermittent voltage high Wiring short to positive, MAP sensor
P1107 Manifold absolute pressure (MAP) sensor – intermittent voltage low Wiring short to ground, MAP sensor
P1109 Intake manifold air control valve – circuit malfunction Wiring, intake manifold air control valve, ECM
P1111 Intake air temperature (IAT) sensor- intermittent voltage high Wiring short to positive, IAT sensor
P1112 Intake air temperature (IAT) sensor- intermittent voltage low Wiring short to ground, IAT sensor
P1114 Engine coolant temperature (ECT) sensor – intermittent voltage low Wiring short to ground, ECT sensor
P1115 Engine coolant temperature (ECT) sensor- intermittent voltage high Wiring short to positive, ECT sensor
P1121 Throttle position (TP) sensor – voltage high Wiring short to positive, ECT sensor
P1122 Throttle position (TP) sensor – voltage low Wiring short to ground, ECT sensor
P1137 Heated oxygen sensor (H02S) 2, bank 1 – voltage low Wiring, exhaust system leaking, H02S
P1138 Heated oxygen sensor (H02S) 2, bank 1 – rich in deceleration fuel cut-off Fuel system, fuel pressure regulator, leaking injector(s)
P1166 Heated oxygen sensor (H02S) 1, bank 1 – voltage low Wiring, exhaust system leaking, H02S
P1171 Heated oxygen sensor (H02S) control, bank 1 – system too rich Excessive fuel in engine oil, injector leaking, fuel pressure, EVAP canister purge valve, MAP sensor, MAF sensor, H025
P1172 Heated oxygen sensor (H02S) control, bank 1 – system too lean Intake/exhaust leak, injector blocked, MAP sensor, MAF sensor, fuel pressure/pump, H025
P1174 Heated oxygen sensor (H02S) control, bank 2 – system too rich Excessive fuel in engine oil, injector leaking, fuel pressure, EVAP canister purge valve, MAP sensor, MAF sensor, H025
P1175 Heated oxygen sensor (H02S) control, bank 2 – system too lean Intake/exhaust leak, injector blocked, MAP sensor, MAF sensor, fuel pressure/pump, H025
P1231 Fuel pump relay – voltage high Wiring open circuit/short to positive, fuel pump relay
P1320 Crankshaft position (CKP) sensor- signal adaptation at limit Wiring, CKP sensor
P1321 Crankshaft position (CKP) sensor- incorrect signal Wiring, CKP sensor
P1382 Rough road signal – invalid data Wiring, ABS system
P1391 Rough road G-force sensor – implausible signal Wiring, G-force sensor, ECM
P1392 Rough road G-force sensor – voltage low Wiring open circuit/short to ground, G-force sensor, ECM
P1393 Rough road G-force sensor – voltage high Wiring short to positive, G-force sensor, ECM
P1396 Wheel speed sensor deviation, rough road signal – malfunction Wiring, G-force sensor, ECM
P1397 Wheel speed sensor deviation, rough road signal – malfunction Wiring, G-force sensor, ABS control module, ECM
P1420 Evaporative emission (EVAP) canister purge valve – mechanical fault EVAP canister purge valve
P1421 Evaporative emission (EVAP) canister purge valve – mechanical fault EVAP canister purge valve
P1422 Evaporative emission (EVAP) canister purge system – leak detected Wiring, EVAP solenoid, vacuum switch, ECM
P1424 Evaporative emission (EVAP) leak detection pump – signal high Wiring short to positive, EVAP leak detection pump
P1425 Evaporative emission (EVAP) leak detection pump – signal low Wiring short to ground, EVAP leak detection pump
P1443 Evaporative emission (EVAP) canister purge valve – defective Wiring, hoses, EVAP canister purge valve
P1449 Evaporative emission (EVAP) canister purge valve – defective Wiring, hoses, EVAP canister purge valve
P1504 Vehicle speed sensor (VSS) – no signal Wiring, VSS, TCM, ECM
P1510 Engine control module (ECM) -supply voltage Wiring, ECM
P1511 Idle speed control (ISC) actuator – circuit malfunction Wiring, ISC actuator
P1512 Idle speed control (ISC) actuator- malfunction ISC actuator
P1513 Idle speed control (ISC) actuator- functional diagnosis malfunction Wiring, ISC actuator, ECM
P1516 Throttle valve actuator – position performance Throttle valve tight/sticking, TP sensor, wiring, throttle control unit, ECM
P1562 Engine control module (ECM) – battery voltage low Wiring, ECM
P1563 Engine control module (ECM) – battery voltage high Wiring, alternator, ECM
P1610 Engine control (EC) relay – voltage high Wiring open circuit/short to positive, EC   relay
P1611 Engine control (EC) relay- voltage low Wiring short to ground, EC relay
P1614 Transponder response error Ignition key not programmed, incorrect ignition key, transponder, immobilizer control module, ECM
P1615 Steering lock – communication malfunction Wiring, steering lock, keyless start control module, ECM
P1616 Keyless start control module – not coded Ignition key not programmed, keyless start control module, ECM
P1618 Keyless start control module – CAN circuit malfunction Wiring, keyless start control module, ECM
P161B Engine torque control – limit reached/exceeded Intake air leak, electronic throttle system   (ETS), exhaust blockage, ECM
P1621 Immobilizer control module/engine control module (ECM) – communication malfunction Wiring, fuse, immobilizer control module, ECM
P1622 Engine control module (ECM) – EEPROM   error ECM
P1623 Ignition key not programmed Ignition key not programmed, incorrect ignition key, immobilizer control module, ECM
P1625 Immobilizer control module – antenna malfunction Immobilizer control module, ECM
P1636 Immobilizer information registration malfunction Wiring – controller area network (CAN) data bus, body control module (BCM), ECM, ABS control module
P1638 Immobilizer information misn:Jatched Wiring – controller area network (CAN) data bus, body control module (BCM), ABS control
P1645 Immobilizer information error Wiring – controller area network (CAN) data bus, immobilizer controller, ECM
P1646 Immobilizer information mismatched Wiring – controller area network (CAN) data bus, immobilizer controller, ECM
P1650 Engine control module (ECM)- MIL circuit high voltage Wiring, engine malfunction indicator lamp   (MIL}, ECM
P1668 Engine coolant temperature (ECT) sensor – signal malfunction Wiring, ECT sensor, ECM
P1670 CAN data bus, ABS communication – missing Wiring, ECM, ABS control module
P1671 CAN data bus, TCM communication – missing Wiring, ECM, TCM
P1672 CAN data bus – bus off mode detected
P1673 CAN data bus – communication malfunction Wiring, ECM, TCM
P1702 Transmission control module (TCM) – memory check suni error TCM
P1723 Transmission range (TR) switch – malfunction Wiring, TR switch, ECM