First ? be sure the key is in the RUN position, and/or start engine.
If that does not solve the problem, then the ECU may not responding properly. You may need to manually set, or ?Force?, the operating MODE of your ScanGauge. Please refer to the user manual for your ScanGauge for information on how to access the MODE setting screen. Once you are ready to set the mode, you can try the following settings:
FORD Products: PWM or CANSF
GM Products: VPW , ISO or CANSF
Chrysler Products: ISO, VPW or CANSF
Volvo Products: ISO, CANSF or CANLF
Others: ISO, KWPS, KWPF, CANSF, CANLF, CANSS or CANLS
Next ? confirm your vehicle meets the minimum OBDII, OBD2 or EOBD compatibility requirements. Click the following link if your vehicle is 1995 or older, or click this link if your vehicle 1996 or newer.