Code 81, QDM Fault (Solenoid "B"): Notes

The PCM/TCM continually monitors voltage on each circuit connected to the quad driver, looking for either low or high voltage, depending on the commanded state of the devices connected to it. Code 81 will set if a fault has been detected on the shift solenoid "B" circuit. For example, if shift solenoid "B" is commanded on by the PCM/TCM, voltage on that circuit should drop when solenoid is grounded. If voltage stays up for at least .5 second, Code 81 will set. The opposite is also true. If shift solenoid "B" is off, voltage on the circuit should remain high. If voltage drops for more than .5 second, Code 81 will set.

1. This procedure checks shift solenoid "B" and internal transmission wiring for shorts.
2. This test checks for power, from the ignition through transmission fuse, to the shift solenoid "B".
3. This test ensures circuit No. 1223 is not shorted to ground.
4. This test checks PCM/TCM's ability to ground or control shift solenoid "B". If bidirectional Scan tester is not available, solenoid may be activated by grounding ALDL test terminal "B" with ignition on and engine off.
5. This test ensures circuit No. 1223 is not shorted to ground.