How to Diagnose Suzuki OBD1 Year 1991-1999 Without OBD Scanner

HOW TO DIAGNOSE ISUZU OBD1 WITHOUT OBD SCANNER FROM YEAR 1991-1999

How to Diagnose Suzuki OBD1 Year 1991-1999 Without OBD Scanner

Preparatory conditions

Ensure battery voltage above 11 volts.
Transmission in neutral.
All auxiliary equipment, including air conditioning, switched OFF.

Method 1 – except Germany

  • Trouble codes are displayed by the malfunction indicator lamp (MIL).FIG3
  • Switch ignition ON.
  • Check that MIL illuminates.
  • Install a spare fuse to diagnosis socket in fusebox Fig. 1 [1].
  • Count MIL flashes. Note trouble codes. Compare with trouble code table.
  • Each trouble code consists of two groups of one or more flashes.FIG.2
  • A 1,5 second pause separates each trouble code group.
  • A 3 second pause separates each trouble code.
  • MIL flash duration: 0,3 second.
  • For example: Two 0,3 second flashes – 1,5 second pause – one 0,3 second flash. Trouble code 21.
  • Remove fuse.
  • Switch ignition OFF.

Method 2 – Germany

  • Trouble codes are displayed by the malfunction indicator lamp (MIL).FIG3
  • Switch ignition ON.
  • Check that MIL illuminates.
  • Install a spare fuse to diagnosis socket in fusebox Fig. 1 [1].
  • Bridge diagnosis connector terminals Fig. 1 [2].
  • Count MIL flashes. Note trouble codes. Compare with trouble code table.
  • Each trouble code consists of two groups of one or more flashes.FIG2
  • A 1,5 second pause separates each trouble code group.
  • A 3 second pause separates each trouble code.
  • MIL flash duration: 0,3 second.
  • For example: Two 0,3 second flashes – 1,5 second pause – one 0,3 second flash. Trouble code 21.
  • Remove fuse. Remove bridge wire.
  • Switch ignition OFF.

Erasing trouble codes

  • Ensure ignition switched OFF.
  • Disconnect battery earth lead for 20 seconds minimum.
  • Reconnect battery earth lead.
  • Repeat checking procedure to ensure no data remains in ECM fault memory.

WARNING: Disconnecting the battery may erase memory from electronic units (e.g. radio, clock).

OBD1 CODES

Trouble code

Fault location

Probable cause

12No fault found
13Heated oxygen sensor (HO2S) – circuit malfunctionWiring, HO2S, ECM
14Engine coolant temperature (ECT) sensor – circuit malfunctionWiring, ECT sensor, ECM
15Engine coolant temperature (ECT) sensor – signal malfunctionWiring, ECT sensor, ECM
21Throttle position (TP) sensor – signal voltage highWiring, TP sensor, ECM
22Throttle position (TP) sensor – signal voltage lowWiring, TP sensor, ECM
23Intake air temperature (IAT) sensor – circuit malfunction/intermittent voltage highWiring, IAT sensor, ECM
24Vehicle speed sensor (VSS) – signal malfunctionWiring, VSS, ECM
25Intake air temperature (IAT) sensor – circuit malfunction/intermittent voltage lowWiring, IAT sensor, ECM
31Manifold absolute pressure (MAP) sensor – signal voltage lowWiring, MAP sensor, ECM
32Manifold absolute pressure (MAP) sensor – signal voltage highWiring, MAP sensor, ECM
33Mass air flow (MAF) sensor – signal voltage highWiring, MAF sensor, ECM
34Mass air flow (MAF) sensor – signal voltage lowWiring, MAF sensor, ECM
41Ignition fail safe signal – circuit malfunctionWiring, noise suppressor, ignition control module (ICM), ECM
42Crankshaft position (CKP) sensor/camshaft position (CMP) sensor
– signal malfunction
Wiring, CKP/CMP sensor, ECM
44Closed throttle position (CTP) switch – signal malfunctionWiring, CTP switch, ECM
45Closed throttle position (CTP) switch – signal malfunctionWiring, CTP switch, ECM
51Exhaust gas recirculation (EGR) solenoid – circuit malfunctionWiring, EGR solenoid, ECM
52Injector leak/heated oxygen sensor (HO2S) – circuit malfunctionWiring, injector/HO2S, ECM
Light remains ONEngine control module (ECM)ECM