LEMON Manuals: Even more car manuals for everyone
Home >> Nissan-Datsun >> 1987 >> Pickup Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> ECC CEC System >> Testing & Diagnosis Description >> Cautions

Testing & Diagnosis Description: 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.

TROUBLE CODE IDENTIFICATION CHART

Code Go To Test Malfunctioning Component
11 A  Crank Angle Sensor
12 B  Mass Airflow Neter
13 C  V6 Cylinder Head Temperature Sensor
21 E  V6 Ignition Signal/Knock Sensor
22 F (3) Fuel Pump
(2) G  Idle Switch
32 J  EGR Function
33 K  Exhaust Gas Sensor
35 L  Exhaust Gas Temp. Sensor
42 O  Throttle Position Sensor
43 G  Injector
44 N/A All Clear/No Codes
45 P  Injector Leakage
51 Q  Injector Malfunction
(1) Q  Injector Malfunction
(2) R  Start Signal
(1) S Air Regulator
(1) T Auxiliary Air Control Valve
(1) U  Spark Plug Switching
(1) V  Power & Ground Circuits
(1) W EGR Control
(1) X  Idle-Up Control
(1) Y  Air Injection Valve
(1) Z  Clutch/Neutral/Inhibitor Switches
(1) AA IAA or FICD Control
(1) BB  Main Relay
(1) CC Pressure Regulator Control
(1) DD  Fuel Pump Relay
(1) EE  Load Signal
(1) FF Power Valve Control
(1) GG A/C & P/S Switches
(1) HH  Mixture Heater
(1) II  Mixture Heater Relay
(1) JJ  Fuel Pump
(1) Does not set a trouble Code (non-self-diagnostic item).
(2) Does not set a trouble Code (switch on/off diagnosis).
(3) All models do not set a Code 22 for fuel pump malfunctions. Use test JJ for vehicles with fuel pumps that are non self-diagnostic items.