ECU Cold Start Operation

Fig. 8 Thermometer connection:

Object: Check that during cold start (coolant temperature less than 18°C) the OCR is fixed at 50%


1. Connect the bypass harness 8.0141 P, the OCR or dwell meter, and the thermometer 8.0141 BG, Fig. 8, which is to be mounted in series on the hose going from the water pump (1) to the water jacket (2).
2. Activate the by-pass harness 8.0141 P switch and start the engine. If the engine is cold, (less than 18°C), the OCR reading should be 50% (45°).

Fig. 9 Ohmeter test, pin # 12:

Fig. 27 Thermocontact switches:

3. If this is not the case, check the connection of wire 47 R on Pin #12 of connector (8a), Fig. 9, the continuity of wire 47 R, Fig. 9, and the operation of the thermocontact (7), Fig. 27.
4. When the coolant temperature reaches 16°C to 20°C, (61°F to 68°F), the OCR Meter should indicate a variation of the regulation.
5. If this is not so, check the connection between the control box and the Lambda sensor and the condition of the sensor.
6. If the engine is hot (coolant temperature greater than 18°C). Disconnect wire 47C from the thermocontact (7), Fig. 27, and put it to ground. The OCR meter should read 50%.
7. If this is not the case, check the connections of wire 47 R on Pin #12 of the connector (8a), Fig. 9, the continuity of wire 47R, Fig. 9, and the operation of the thermocontact (7), Fig. 27.

Fig. 10 Thermocontact test:

8. Check the thermocontact as follows:
a. Make a test hook-up as shown, Fig. 10.
b. When the water temperature reaches 16°C to 20°C, (61°F to 68°F), it should open the circuit and shut off the test light.
c. If thermocontact fails the above test, replace the unit.