SC L4-1.9L DOHC VIN 7 (1991)
Technical Service Bulletin # 91-T-18
Date: 910601
Coolant Temperature Gage - At or On the Red Mark
NO.:
91-T-18
DATE:
June, 1991
GROUP:
Engine
CORP. NO.:
188302
SUBJECT:
Coolant Temperature Gage Needle at, or on the RED Mark (Diagnose Coolant Temperature Sensor Circuits) - 1991 Saturns
CONDITION:
Customers express concern that vehicle is overheating since temperature gage needle is at, or on the RED mark of the temperature
gage.
CORRECTIVE
ACTION:
Diagnose engine coolant temperature indicator sensor, coolant temperature gage, powertrain control module and/or coolant
temperature indicator - PCM sensor (CTS) according to the following procedures.
FIGURE 1
NOTE:
The normal operating range of the engine coolant temperature gage is shown in Figure 1. When the gage reads just above 3/4 mark, the
coolant should be approximately 105.5~C (222~F) and the engine cooling fan should turn on and cool the cooling system. The engine
cooling fan will turn off at approximately 100.5~C (213~F), and the temperature gage should read around the 1/2 mark.
Diagnosis Procedure: