DTC B1715: Coolant Temperature Signal Fault
- Disconnect coolant temperature sensor. Connect test light between battery positive voltage and coolant temperature sensor connector terminal No. 1 (Yellow/Gray wire). See Fig 1
. If test light comes on, go to next step. If test light does not come on, repair open circuit in Yellow/Gray wire between Main Instrument Unit (MIU) 22-pin connector terminal No. 7 and coolant temperature sensor connector terminal No. 1. See Figure
.
- Using Tech 1 scan tool, read coolant temperature sensor value. If a reading of -40°F (-40°C) is obtained, go to next step. If a reading of -40°F (-40°C) is not obtained, connect jumper wire between coolant temperature sensor connector terminals No. 1 (Yellow/Gray wire) and No. 2 (Yellow/Brown wire). If scan tool displays a temperature of 302°F (150°C), replace coolant temperature sensor. After repair, go to next step. If scan tool does not display a temperature of 302°F (150°C), repair open circuit in Yellow/Brown wire between MIU 22-pin connector terminal No. 15 and coolant temperature sensor terminal No. 2. After repair, go to next step.
- Use scan tool to clear all DTCs. Perform a functional test to determine whether DTC reoccurs. If DTC does not reoccur, system is okay. If DTC reoccurs, replace MIU ECU. See ELECTRONIC CONTROL UNIT (ECU)
under REMOVAL & INSTALLATION.
Courtesy of SAAB-SCANIA OF AMERICA, INC.