Code 140, Phone System Problem (Optional)

Code B140 will set if the ignition is on and PWM signal on circuit No. 901 to the BCM is indicating Mode 7 (BCM Data Display BD45). This code will also set if the CRTC does not get a message back from the phone over the E & C data bus when you try to turn power on or off, or try to lock the phone from the CRT.

1. Determines if there is a data bus problem or just a phone problem.
2. Determines if the code set is due to the phones hardware signal to the BCM or because of communication problem.
3. Since the phone should work on its own as the CRTC is just an alternative way of dialing, try to work the phone from the handset. This will determine if the phone is the problem or if there is a data bus problem isolating the CRTC from the phone.

Fig 1: Code B140, Phone System Problem (Optional)