1-4 Shift System Check (Manual Transmission Corvette)
- With engine off, depress clutch and place transmission in 1st gear. Shift transmission into 2nd or 3rd gear. If transmission cannot be shifted into 2nd or 3rd gear, check for short to voltage on circuit No. 138 between 1-4 shift relay and 1-4 shift solenoid, defective 1-4 shift solenoid, or internal mechanical transmission problem. See Figure.
- Turn ignition on with engine not running. Ground ALDL "test" terminal "B". Shift transmission into 2nd or 3rd gear. If transmission cannot be shifted into 2nd or 3rd gear, system is functioning correctly.
- If transmission can be shifted into 2nd and 3rd gear, turn ignition off. Disconnect 1-4 shift relay connector. Turn ignition on and check for voltage from ground to harness terminals "D" and "E". If voltage is not present on both harness terminal, check for blown fuses or open circuit to terminal which did not illuminate test light.
- If test light illuminated when touched to both terminals, ground ALDL "test" terminal "B" and connect test light from battery voltage to terminal "F" of 1-4 shift relay harness connector.
- If test light does not illuminate, check for open in circuit No. 108 between relay and ECM, poor ECM terminal contact or defective ECM. If test light did illuminate, perform 1-4 SHIFT RELAY test procedures.