C70, S70 & V70 (Temperature Gauge Reading Incorrect)

Check ground circuit between instrument cluster 30-pin connector terminal A15 (Brown wire) and ground. Repair as necessary. In addition, check temperature signal from Motronic ECU at connector terminal B23 (Green/Gray wire). With ignition on, digital signal of 5-6 volts to 15 volts should be present. If signal voltage is incorrect, check Motronic ECU. See ENGINE PERFORMANCE article. If signal voltage and ground are okay, replace instrument cluster. See INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION.