FI118 TROUBLESHOOTING FOR EFI ELECTRONIC CIRCUIT WITH VOLT/OHMMETER HINT: Because the following troubleshooting procedures are designed for inspection of each separate system, the actual troubleshooting procedure may vary somewhat. However, please refer to these procedures and perform actual troubleshooting, conforming to the inspection methods described. For example, it is better to first make a simple check and should be replaced. of the fuses, fusible links and connecting condition of the connectors before making your inspection according to the procedures listed. The following troubleshooting procedures are based on the supposition that the trouble lies in either a short or open circuit in a component outside the computer or a short circuit within the computer. If engine trouble occurs even though proper operating voltage is detected in the computer connector, then the engine (engine and ECT) ECU is faulty and should be replaced. LOCATION OF FUSES AND FUSIBLE LINK
FI119 CHECK PROCEDURE HINT: Perform all voltage measurements with the connector connected. Verify that the battery voltage is 1 1 V or more when th ignition switch is in ON position. Using a voltmeter with high impedance (10 k V minimum measure the voltage at each terminal of the wiring connectors. of Engine (Engine and ECT) ECU Symbol Terminal name ENGINE GROUND ENGINE GROUND INJECTOR INJECTOR Symbol Terminal name NEUTRAL START SWITCH IGNITER SPEED SENSOR DISTRIBUTOR ENGINE GROUND DISTRIBUTOR VSV (for A/C) DISTRIBUTOR OXYGEN SENSOR HEATER DISTRIBUTOR VSV (for AS) CHECK CONNECTOR COLD START INJECTOR CHECK CONNECTOR VSV (FOR EGR) T/M OIL TEMP. SENSOR VSV (for FPU ) CHECK CONNECTOR IGNITER OXYGEN SENSOR ECT SOLENOID TIM OIL TEMP. SENSOR TRANSFER POSITION SWITCH KNOCK SENSOR ECT SOLENOID EGR GAS TEMP. SENSOR NEUTRAL START SWITCH WATER TEMP. SENSOR ECT SOLENOID THROTTLE POSITION SENSOR NEUTRAL START SWITCH AIR TEMP. SENSOR ECT SOLENOID THROTTLE POSITION SENSOR * : A/T only *2: 4WD A/T only *3: California only *4: 4WD only Symbol Terminal name AIR FLOW METER AIR FLOW METER SENSOR GROUND STARTER SWITCH COMPRESSOR SWITCH CRUISE CONTROL COMPUTER SPEED SENSOR CHECK CONNECTOR 4WD SWITCH A/C AMPLIFIER PATTERN SELECT SWITCH STOP LIGHT SWITCH CHECK ENGINE WARNING LIGHT CRUISE CONTROL COMPUTER A/T OIL TEMP. WARNING LIGHT SENSOR GROUND MAIN RELAY BATTERY + B MAIN RELAY Engine (Engine and ECT) ECU
FI120 Voltage at Engine (Engine and ECT) ECU wiring connectors STD voltage See page Ignition SW ON FI121 Throttle valve open Ignition SW ON Throttle valve fully closed Throttle valve fully open FI123 Ignition SW ON IG SW ON IG SW ON Measuring plate fully closed Measuring plate fully open Idling Intake air temperature 20 C (68 F) Coolant temperature 80 C (1 761F) Ignition SW START position FI125 FI127 FI128 Ignition SW ON FI129 Cranking or idling FI130 No trouble ( CHECK ENGINE warning light off) and engine running FI131 Ignition SW START position Coolant temperature 80 C (1 76 F) Stop light switch ON FI132 FI133
FI121 BATT E 1 There is no voltage between ECU terminals BATT and E1. Check that there is voltage between ECU terminal BATT and body ground. Check wiring between ECU terminal E1 and body ground. Check fuse and fusible link. Replace. Check wiring between fuse and ECU.
FI122 + B (+B1 ) E 1 There is no voltage between ECU terminals +B (+B1) and E1. (IG SW ON) Check that there is voltage between ECU terminal +B (+B1) and body ground. ( IG SW ON) Check wiring between ECU terminal E1 and body ground. Check fuse, fusible link and ignition switch. Check EFI main relay. Replace. Check wiring between EFI main relay and battery. Check wiring between EFI main relay and ECU terminal +B (+B1).
FI123 Trouble STD Voltage Throttle valve open No voltage Ignition switch ON Throttle valve fully closed Throttle valve fully open. IDL E2 (E21) There is no voltage between ECU terminals IDL and E2 (E21). (IG SW ON) (Throttle valve open) Check that there is voltage between ECU terminal + B1 (+B) and body ground. (IG SW ON) Refer to 1. Replace or repair. Check wiring between ECU terminal El and body ground. Check throttle position sensor. Replace or repair. Replace or repair throttle position sensor. Check wiring between ECU and throttle position sensor.
FI124 Vc E2 (E21) There is no voltage between ECU terminals Vc and E2 (E21). (IG SW ON) Check that there is voltage between ECU terminals + B1 (+B) and E1. (IG SW ON) Check throttle position sensor. Refer to 1. Check wiring between ECU and throttle position sensor. Repair or replace wiring. VTA E2 (E21) There is no voltage between ECU terminals VTA and E2 (E21 ). (IG SW ON) Check that there is voltage between ECU terminals Vc and E2 (E21). (IG SW ON) Perform inspection of Vc E2 (E21) Check throttle position sensor. Check wiring between ECU and throttle position sensor.
FI125 Trouble STD Voltage No voltage Ignition SW ON IG SW ON Measuring plate fully closed Measuring plate fully open Idling Intake air temperature 20 C (68 F) Vc E2 (E21) There is no voltage between ECU terminals Vc and E2 (E21 (IG SW ON) Check that there is voltage between ECU terminals +B (+B1 ) and body ground. (IG SW ON) Check air flow meter. Refer to 1. Replace or repair air flow meter. Check wiring between ECU and air flow meter. Replace or repair wiring.
FI126 Vs E2 (E21) There is no specified voltage between ECU terminals Vs and E2 (E21). (IG SW ON) Check that there is voltage between ECU terminals Vc and E2 (E21). (IG SW ON) Refer to Vc E2 (E21) Repair or replace Check air flow meter. Repair or replace Check wiring between ECU and air flow meter. Repair or replace THA E2 (E21) There is no voltage between ECU terminals THA and E2 (E21). (IG SW ON) Check that there is voltage between ECU terminal +B (+B1) and body ground. (IG SW ON) Check air temp. sensor. Refer to 1. Replace air flow meter. Check wiring between ECU and air temp. sensor. Repair or replace wiring.
FI127 Trouble STD Voltage No voltage Ignition switch ON Coolant temperature 80 C (176 F) There is no voltage between ECU terminals THW and E2 (E21 ). (IG SW ON) Check that there is voltage between ECU terminal +B (+B1) and body ground. (IG SW ON) Refer to 1. Check wiring between ECU terminal E1 and body ground. Check water temp. sensor. Replace water temp. sensor. Check wiring between ECU and water temp. sensor.
FI128 Trouble STD Voltage No voltage Ignition switch START position There is no voltage between ECU terminals STA and E1. (IG SW START) Check starter operation. Check wiring between ECU terminal STA and starter terminal 50. Check wiring between ECU terminal E1 and bod ground. Check fusible link, battery, wiring and ignition switch. Check that there is voltage at terminal 50 of starter. (IG SW START) STD voltage: 9 11 V Check starter. Check wiring between ignition switch ST1 terminal and starter terminal 50.
FI129 Trouble STD Voltage No voltage Ignition switch ON There is no voltage between ECU terminals 10 and/or 20 and E01 and/or E02 (IG SW ON) Check that there is voltage between ECU terminal 10 and/or 20 and body ground. Check wiring between ECU terminal E01 and/or E02 and body ground. Check fusible link and ignition switch. Check resistance of magnetic coil in each injector. STD resistance: 13.4 14.2 Ω Replace injector. Check wiring between ECU terminal 10 and/or 20 and battery.
FI130 Trouble STD Voltage No voltage Cranking or Idling There is no voltage between ECU terminals IGt and E1. (Idling) Check that there is voltage between ECU terminal IGt and body ground. (Idling) (3) Check wiring between ECU terminal E1 and body ground. Refer to 1. Check wiring between igniter and distributor. Check distributor. Replace. Check wiring between ECU and igniter. Check igniter.
FI131 Trouble STD Voltage No voltage No trouble (CHECK ENGINE warning light off) and engine running There is no voltage between ECU terminals w and E1. (Idling) Check that there is voltage between ECU terminal W and body ground. (3) Check wiring between ECU terminal E1 and body ground. Check GAUGE fuse (10A) and CHECK ENGINE warning light. Check wiring between ECU terminal W and fuse. Fuse blows again
FI132 Trouble STD Voltage No voltage Ignition switch START position Coolant temperature 80 C (176 F) There is no voltage between ECU terminals STJ and E1. (IG SW START) Check that there is voltage between ECU terminal +B (+B1 ) and body ground. (IG SW ON) Check cold start injector. Refer to 1. Replace cold start injector Check wiring between ECU and cold start injector. Check wiring between ECU terminal E1 and body ground. Repair or replace wiring.
FI133 Trouble STD Voltage No voltage Stop light switch ON There is no voltage between ECU terminals STP and E1. Check that there is voltage between ECU terminal STP and body ground when the brake pedal is depressed. Check wiring between ECU terminal E1 and body ground. Check STOP fuse (1 5A) and stop light switch. Check wiring between ECU terminal STP and battery.
FI134 There is no voltage between ECU terminals VF and E I. Check that there is voltage between ECU terminal VF and body ground. Check wiring between ECU terminal E1 and body ground. Is air leaking into air induction system? YES Repair air leak. Check spark plugs. Check distributor and ignition system. OK CONTINUED ON PAGE FI135.
FI135 CONTINUED FROM PAGE FI134. Check fuel pressure. Check injector. Check cold start injector.* Check air flow meter. Check operation of oxygen sensor. Check wiring between oxygen sensor and ECU connector. System normal. Repair wiring. Replace oxygen sensor. * Rich malfunction only
FI136 There is no voltage between ECU terminals THG and E2 (E20 (Engine running at 2,000 rpm) Check that there is voltage between ECU terminal +B (+B1) and body ground. (IG SW ON) Refer to 1. Check wiring between ECU terminal E1 and body ground. Check EGR system. Check EGR gas temp. sensor. Replace EGR gas temp. sensor. Check wiring between ECU and EGR gas temp. sensor.