E029

TEST CONDITIONS
1. Code EO24 not set;
2. Transmission in drive or reverse;
3. ECM is commanding third gear;
4. Vehicle speed is equal to or greater than 0 MPH;

FAILURE CONDITIONS Third gear input to ECM grounded. (3rd gear not present) for 6 seconds.

ACTION TAKEN
1. ECM turns on "Engine Control System Fault" telltale;
2. ECM commands BCM to display "Service Soon" message on Driver Information Center (DIC).
3. Cruise control is disabled;
4. Viscous converter clutch is disabled.

DESCRIPTION
The third gear switch is a normally closed (grounded) switch, located in the transmission, that opens when 3rd gear hydraulic oil is applied to it. The third gear switch has 12 volts supplied by the ECM on CKT 108. CKT 108 is grounded when the transmission is not in third gear (switch closed) and has 12 volts on it when the third gear switch opens (3rd gear oil applied).

Code EO29 will set when ECM commands 3rd gear and the switch stays closed.

Possible causes of Code EO29 are:
1. CKT 108 grounded;
2. CKT 697 open or grounded;
3. Faulty 3rd gear switch;
4. Faulty 3rd gear shift solenoid or ECM.

Notes on Fault Tree
1. Checking for 2-3 shift solenoid operation.
2. Checking for short to ground in CKT 108.