ECC CEC System: Diagnosis: Cautions
Before connecting or disconnecting ECU harness connector to or from the ECU, be sure that ignition switch is in the "OFF" position and negative battery cable is disconnected or damage to the ECU may result. This is important because battery voltage is applied to the ECU even when the ignition switch is in the "OFF" position.
When performing an ECU input/output signal inspection, remove pin terminal retainer from connectors. This will make probing of the connector pins easier and safer.
When connecting or disconnecting pin connectors from the ECU, take care not to bend or break any pin terminals. Before replacing ECU, perform the ECU input/output signal inspection to be sure ECU is malfunctioning.
When measuring voltage supply to ECU controlled components, be sure not to touch probe testers together. Separating test probes is helpful. This will prevent accidentally making contact between the 2 probes, causing a shorted circuit and damaging the ECU.
| Code No. | Test Letter | Malfunctioning Component | ||||
|---|---|---|---|---|---|---|
| 11 | A | Crank Angle Sensor | ||||
| 12 | B | Mass Airflow Sensor | ||||
| 13 | C | Coolant Temp. Sensor | ||||
| 14 | D | Vehicle Speed Sensor | ||||
| 21 | E | Ignition Signal/Knock Sensor | ||||
| 23 | G | Idle Switch | ||||
| 25 | I | Idle Speed Control Valve | ||||
| 31 | H | ECU Malfunction | ||||
| 33 | K | Exhaust Gas Sensor | ||||
| 43 | O | Throttle Position Sensor | ||||
| 55 | ..... | No Malfunctions Indicated | ||||
| (1) | Q | Injector Malfunction | ||||
| (2) | R | Start Signal | ||||
| (1) | V | Power & Ground Circuits | ||||
| (1) | W | EGR Control | ||||
| (1) | Y | Air Injection Valve | ||||
| (1) | Z | Clutch/Neutral/Inhibitor Switches | ||||
| (1) | DD | Fuel Pump Relay | ||||
| (1) | GG | A/C & P/S Switches | ||||
| (1) | HH | Mixture Heater | ||||
| (1) | II | Mixture Heater Relay | ||||
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