Light indication does not work on the 5th (higher) transmission and heavy engine braking. On models manufactured in 1984 and later, the indicator light works in all gears except reverse.
Pic. 8.7. The nodes that are part of the economy driving mode indication system: 1 - to the spark plug; 2 - ignition coil; 3 - damper (delay valve); 4 - vacuum switch; 5 - suction pipe; 6 - 5th gear enable sensor; 7 – forced idle economizer switch; 8 - carburetor; 9 - storage battery; 10 - ignition switch; 11 - control unit; 12 - indicator of excessive opening of the throttle; 13 – the index of inclusion of the increased transfer; 14 - to the control lamp switch
In addition to the indicator lights themselves, the main components of the system are: a control unit located under the switch panel or instrument panel; vacuum operated switch connected to the suction port via a damper (delay valve); 5th gear enable sensor mounted on the gearbox; positive idle economizer switch mounted on carburetor (pic. 8.7).
The control unit and the forced idle economizer switch are combined with the air-fuel mixture leaner when driving in neutral.
The control unit receives signals from the sensor and switches, voltage from the power supply and signals from the ignition coil. The signal from the ignition coil ensures that the control unit monitors the speed of the crankshaft.
Checking the technical condition
Control lamp of inclusion of the increased transfer
Start the engine and set to idle.
Gradually increase the engine speed and check that the upshift warning light comes on at 2800 rpm-1 and stays on when the engine speed is increased further.
Pic. 8.8. Location of the connector for the 5th gear enable sensor, which is part of the economy driving mode indication system
Disconnect the connector from the 5th gear enable sensor (located next to the battery) and recheck (pic. 8.8). The control lamp should not light up. Connect the connector.
Excessive Throttle Opening Warning Lamp
This check will require a vacuum pump and gauge.
Pic. 8.9. Checking the vacuum switch of the economy driving display system
Disconnect the vacuum hose from the switch and connect the vacuum pump and vacuum gauge instead (pic. 8.9). Turn on the ignition. An assistant will be required to observe the test lamp during the increase in vacuum in the switch. The control lamp should light up when the vacuum is from 0 to 120 mm Hg. Art. and extinguish as the vacuum increases.
Pic. 8.10. Location of the 5th gear enable sensor
On pre-1984 models, disconnect the connector from the 5th gear engagement sensor and recheck (pic. 8.10). The control lamp should not light up. Connect the connector and vacuum hose to the 5th gear enable sensor.
Replacing nodes
Pilot lamps and pointers
Remove glass of a combination of devices and replace a control lamp.
Vacuum switch
Remove the vacuum hose and disconnect the connector from the switch. Remove the switch from the bracket on the car body.
Install the new switch, connect the hose and connector.
5th gear enable sensor
Along the wire, locate the 5th gear engagement sensor and disconnect the connector from the sensor.
Remove the sensor from the gearbox. Keep in mind that in this case, oil may spill.
Install a new sensor, connect the connector, then check the oil level in the transmission.
Control block
Access to the control unit is possible after removing the lower decorative overlay of the instrument panel, switch panel or instrument cluster.