B1715

Symptom: The temperature gauge always indicates too low a temperature L. Diagnostic trouble code B1311 may be present in the ICE control module. The radiator fan may start when the ignition is switched on.

B1715

Fault symptoms

The temperature gauge always indicates too low a temperature L. Diagnostic trouble code B1311 may be present in the ICE control module. The radiator fan may start when the ignition is switched on.

Diagnostic procedure

1.	Check whether diagnostic trouble code B1311 is present in ICE. If it is, continue fault diagnosis as described in "Electrical system, ICE" .

2.	If the trouble code is not present in the ICE control module, check the temperature signal sent to the main instrument display panel by selecting "MAIN INSTRUMENT" on the Scan Tool followed by "READ VALUES", "COOLANT TEMP."

3.	If the temperature signal is OK, the temperature shown on the Scan Tool's display should correspond to the engine temperature. If it does, continue with point 6.

4.

If -40°C is displayed, there is probably an open circuit or a short circuit to ground in the wiring between the ICE control module and the main instrument display panel. Check the wiring by connecting a BOB to the main instrument display panel's 56-pin connector and another BOB to the ICE control module's 70-pin connector (the main instrument display panel and the ICE control module should not be connected).

5.

Take a reading across pin 7 on the BOB connected to the main instrument display panel's connector and pin 14 on the other BOB. Check for shorting to ground/battery positive by taking a reading across pin 7 on the BOB connected to the main instrument display panel's connector and a good grounding point. If the readings are OK, check whether the fault persists by disconnecting the two BOBs and connecting the control modules to the car's wiring harness. Clear the trouble code and see whether it recurs.

6.	If it does not recur, the fault could have been in one of the connectors. If the trouble code recurs, there may be an open circuit between the connector and the processor in the main instrument display panel's control module. Continue fault diagnosis as described on .