Code 26 - Quad-Driver Error (1 Of 3): Notes

Each ECM Quad-Driver Module (QDM) has a fault line which is monitored by ECM. ECM compares voltage values of fault line with acceptable values in ECM memory. If ECM senses values other than accepted values, a Code 26 will set. QDM "B" will not set a Code 26.

1. ECM does not know which controlled circuit set Code 26. This tests SERVICE ENGINE SOON light driver and circuit.
2. QDM symptoms:
   • TCC inoperative (Code 39).
   • Hot light/check gauges light always on, off during bulb check.
   • Cooling fan always on or will not come on at all.
   • Poor driveability due to 100 percent canister purge.