Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSHYUNDAI1990EXCEL BASE, 4D SEDAN, STANDARDREPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMENGINE CONTROLS - TESTS W/CODESSELF-DIAGNOSTIC SYSTEMRETRIEVING CODES

1990 Hyundai Excel Base, 4D Sedan, Standard

Retrieving Codes

1990 Hyundai Excel Base, 4D Sedan, StandardSECTION Retrieving Codes

NOTE: Ensure battery voltage is proper before retrieving codes.

Turn ignition switch to OFF position. Connect either a voltmeter between MPI diagnostic terminal and ground terminal of diagnostic connector, or multi-use tester (scan tool) to diagnostic connector and cigarette lighter. See Fig 1 . Turn ignition switch to ON position and disclosure of ECU memory (fault codes) will begin.

Fig 1: Locating Self-Diagnostic Connector
Courtesy of HYUNDAI MOTOR CO.
If using voltmeter to retrieve fault codes, it is important that voltage signals are accurately timed. Signals will appear in long and short pulses. Long pulses represent a numeral 10, whereas short pulses represent a numeral one. An example of fault code 15 would be one long pulse along with 5 short pulses.
If using scan tool, and malfunction indicator light comes on while various checks are being made, check self-diagnostic output.
After all checks have been made and/or trouble codes recorded, make necessary repairs. After repairs have been made, retest component(s) to ensure problem has been corrected.

DIAGNOSTIC CODE - EXCEL ⁽¹⁾

Code Number

Fault Item

⁽²⁾ Probable Cause

See:

11

O2 Sensor

Fuel Pres., Injectors, Vacuum Leak, O2 Sensor

12

Airflow Sensor

Airflow Sensor

13

Intake Air Temperature Sensor

Intake Air Temperature Sensor

14

Throttle Position Sensor

Throttle Position Sensor, Idle Switch

Figure and Figure

15

Motor Position Sensor

Motor Position Sensor

21

Coolant Temperature Sensor

Coolant Temperature Sensor

22

Crank Angle Sensor

Crank Angle Sensor

Figure and Figure

23

TDC Sensor (No. 1 Cylinder)

Distributor

-

24

Vehicle Speed Sensor Reed Switch

Vehicle Speed Sensor Reed Switch

-

25

Barometric Pressure Sensor

Barometric Pressure Sensor

41

Fuel Injector

Injector Coil Resistance

Figure and Figure

42

Fuel Pump

Control Relay

43

EGR Temperature Sensor (Calif. Only)

EGR Temp. Sensor, Vlv., Ctrl. Sol., Ctrl. Vac.

⁽¹⁾	No fault codes in memory will be indicated by 9 short voltmeter pulses. Faulty ECU will be indicated by a continuous voltage reading on voltmeter.

⁽²⁾	Component, harness and connector are always a probable cause for setting a fault code.

DIAGNOSTIC CODE - SONATA 2.4L ⁽¹⁾

Code Number

Fault Item

⁽²⁾ Probable Cause

See:

11

O2 Sensor

Fuel Pres., Injectors, Vacuum Leak, O2 Sensor

12

Airflow Sensor

Airflow Sensor

13

Intake Air Temperature Sensor

Intake Air Temperature Sensor

14

Throttle Position Sensor

Throttle Position Sensor, Idle Switch

15

Motor Position Sensor

Motor Position Sensor

Figure and Figure

21

Coolant Temperature Sensor

Coolant Temperature Sensor

22

Crank Angle Sensor

Crank Angle Sensor

Figure and Figure

23

TDC Sensor (No. 1 Cylinder)

Distributor

-

24

Vehicle Speed Sensor Reed Switch

Vehicle Speed Sensor Reed Switch

-

25

Barometric Pressure Sensor

Barometric Pressure Sensor

41

Fuel Injector

Injector Coil Resistance

Figure and Figure

42

Fuel Pump

Control Relay

43

EGR Temperature Sensor (Calif. Only)

EGR Temp. Sensor, Vlv., Ctrl. Sol., Ctrl. Vac.

⁽¹⁾	No fault codes in memory will be indicated by 9 short voltmeter pulses. Faulty ECU will be indicated by a continuous voltage reading on voltmeter.

⁽²⁾	Component, harness and connector are always a probable cause for setting a fault code.

DIAGNOSTIC CODE - SONATA 3.0L ⁽¹⁾

Code Number

Fault Item

⁽²⁾ Probable Cause

See:

11

O2 Sensor

Fuel Pres., Injectors, Vacuum Leak, O2 Sensor

12

Airflow Sensor

Airflow Sensor

13

Intake Air Temperature Sensor

Intake Air Temperature Sensor

14

Throttle Position Sensor

Throttle Position Sensor, Idle Switch

21

Coolant Temperature Sensor

Coolant Temperature Sensor

22

Crank Angle Sensor

Crank Angle Sensor

Figure and Figure

23

TDC Sensor (No. 1 Cylinder)

Distributor

-

24

Vehicle Speed Sensor Reed Switch

Vehicle Speed Sensor Reed Switch

-

25

Barometric Pressure Sensor

Barometric Pressure Sensor

41

Fuel Injector

Injector Coil Resistance

Figure and Figure

42

Fuel Pump

Control Relay

43

EGR Temperature Sensor (Calif. Only)

EGR Temp. Sensor, Vlv., Ctrl. Sol., Ctrl. Vac.

⁽¹⁾	No fault codes in memory will be indicated by 9 short voltmeter pulses. Faulty ECU will be indicated by a continuous voltage reading on voltmeter.

⁽²⁾	Component, harness and connector are always a probable cause for setting a fault code.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.