P0756

WITH 4L60-E AUTOMATIC TRANSMISSION

DTC P0756 Shift Solenoid 2-3 - Performance Diagnostic Chart:

Shift Solenoid 2-3 - Wiring Schematic:

Command Chart:

CIRCUIT DESCRIPTION
The 2-3 shift solenoid is used to control fluid flow acting on the 2-3 shift valves. The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations (see third image). The solenoid is attached to the control valve body within the transmission. Ignition voltage is supplied indirectly to the 2-3 shift solenoid. The Vehicle Control Module (VCM-A) controls the solenoid by providing the ground path through CKT 1223. DTC Type (D).

DTC P0756 WILL SET WHEN
- No DTC(s) P0122, P0123, P0502, P0503, P0712, P0713, P1810, P1875.
- Pressure switch assembly indicates D1, D2, D3 or D4.
- Output speed is greater than 7 mph.
- Throttle position is greater than 25%.
- Transmission fluid temp. is greater than 2O°C (68°F).
- Not in 4WD LO.
- First gear commanded ratio is less than or equal to 2.63 for one second, indicating vehicle is in another gear other than commanded 1st.
- Fourth gear commanded ratio is greater than or equal to 2.3 for three seconds, indicating vehicle is in another gear other than commanded 4th.
- Engine running.

ACTION TAKEN (VCM-A will default to)
- VCM-A turns on Malfunction Indicator Lamp (MIL) after 2 consecutive ignition cycles with a fault (if applicable).
- DTC P0756 will be stored in VCM-A memory.

DTC P0756 WILL CLEAR DEFAULT ACTION WHEN
Fault condition(s) no longer exist and the ignition is cycled "OFF" for five seconds, then "ON".

DTC P0756 WILL PASS WHEN
- The VCM-A will report a pass when first gear is commanded and output ratio is greater than 2.63 or fourth gear is commanded and output ratio is less than 2.3.
- The VCM-A turns "OFF" the Malfunction Indicator Lamp (MIL) after three consecutive ignition cycles with reported passes (if applicable).
- All enable criteria are met.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks for the function of the transmission range switch.
2. This test checks for selected gear ratio vs. a ratio not obtainable under normal driving conditions.

COMMANDED GEAR
- First gear ratio should be more than 2.63.
- Fourth gear ratio should be less than 2.3.

DIAGNOSTIC AIDS
Check all connections at VCM-A and transmission. Refer to Intermittents.

NOTE: A 4WD Drive switch/wiring problem may set DTC P0756.