LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis (Single Page) >> Transmission >> Automatic Trans >> Diagnosis - A/T >> Diagnostic Code Charts (Trucks) >> Code 58, Transmission Temperature Sensor Circuit (High Temperature Indicated) - LT. Truck >> Diagnostic Aids

Diagnostic Aids

Check harness routing for a potential short to ground in circuit No. 1227. Scan tester displays transmission temperature in degrees Centigrade. After transmission is running, the temperature display should rise steadily to about 100°C then stabilize. Test the transmission sensor at various temperature levels to determine if sensor is out of calibration See TRANSMISSION SENSOR - TEMPERATURE TO RESISTANCE chart. An out-of-calibration sensor could result in delayed shifts; or TCC enabled complaint.

Fig 1: Code 58, Trans. Temp. Sensor Troubleshooting Chart (High Temp. - Lt. Truck)
G91A13680Courtesy of GENERAL MOTORS CORP.