Exhaust System Temperature Indicator

�G VEXH Warning:

WIRING DIAGRAM

EXH Warning: Component Location:

COMPONENT LOCATION VIEW

EXH Warning: Component ID:

COMPONENT ID

47l EXH warning lamp, in the main instrument display panel.
159 Distribution terminal (+15 circuit), in main fuse box behind the glove box.
416 Relay, EXH warning, located on a bracket behind the front seat member on the right-hand side.
417 Temperature sensor, EXH, on the three-way catalytic converter.

2-Pin Connector
H2-60 To the left under the right-hand front seat.

4-Pin Connector
H4-15 To the left under the right-hand front seat.

Grounding Points
G8 Grounding point, dashboard, by the left-hand front loudspeaker socket.
G24 Grounding point, right-hand seat member, under the right-hand front seat member.

DESCRIPTION OF OPERATION
Cars for certain markets are equipped with a monitoring system for catalytic converter overheating. The system consists of:
^ Temperature sensor 417
^ Electronic relay 415
^ Warning lamp 47l

When catalytic converter temperature reaches 825 +/- 25°C, the warning lamp lights up and remains on until the temperature drops by about 10°C.

When current (+15 circuit) is applied to relay pin 1, the warning lamp is grounded and lights up for about 3 seconds. It does not come on again unless the temperature of the three-way catalytic converter exceeds the set limit.

As the temperature rises, the current flowing between pins 3 and 4 of the temperature sensor changes. When the resistance of the sensor changes by a sufficient amount, the relay function is activated and the warning lamp lights up.

Similarly, the warning lamp goes out when the temperature drops or when current (+15 circuit) is no longer applied to the relay, i.e. when the ignition is switched off.

FAULT DIAGNOSIS HINTS
When current (+15 circuit) is applied to pin 1 of the relay, the warning lamp is grounded and lights up for about 3 seconds. If it remains alight, this indicates a break in the temperature sensor circuit. Normally, the warning lamp will go out and stay out until the temperature exceeds the preset limit.
1. Check that fuse 13 is intact and that the relay and temperature sensor are supplied with current.
2. Also check the connectors, wiring harness and ground connections.