348 Automatic Transmissions and Transaxles Copyright by Goodheart-Willcox Co., Inc. Figure 14-12. Common data provided by the ECM through a scan tool. These readings can be used to quickly isolate a problem area. (General Motors) Typical Scan Tool Data Values Tech 1 Parameter Units Displayed Typical Scan Values MAP kPa 20-48 kPa, depending upon altitude BARO kPa 70-100kPa, depending upon altitude TP sensor Volts 0.3-0.9V TP angle Percent 0% Engine speed RPM +/– 100 RPM from desired idle Desired idle RPM +/– 100 RPM from engine speed Current DTC set Yes/no No ECT sensor Volts Varies TFT C (F) Varies TFT sensor Volts Varies Trans. OSS RPM 0 TCC duty cycle Percentage 0% TCC enable Yes/no No TCC slip speed RPM +/– 50 RPM from the engine speed Brake switch Closed/open Closed TCC ramp Seconds 0.00 TCC apply Seconds 0.00 TCC out of range Yes/no No TCC min. TP Yes/no No TCC delta TP Yes/no No TCC duty open Yes/no No TCC duty shorted Yes/no No TCC enable open Yes/no No TCC enable short Yes/no No Mph (km/h) 0-158 (0-255) 0 MAP sensor Volts 1-2V, depending on altitude Engine run time Hr/min/sec Varies Ignition 1 Volts Varies ECT C (F) Varies PC act. current Amps Varies (0.1-1.1 amps) PC ref. current Amps Varies (0.1-1.1 amps) PC duty cycle Percentage Varies PC sol. low volts Normal/low volts Normal TFP switch A/B/C On/off Off/on/off Power enrichment Yes/no No Cruise enables Yes/no No A/C clutch Yes/no No (Continued)