DTC P0758 2-3 (B) Shift Solenoid Electrical. GMC Truck Safari

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1997 🢒 Safari - 2WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L60-E 🢒 DTC P0758 2-3 (B) Shift Solenoid Electrical

Table 1:	Shift Solenoid Valve State and Gear Ratio 4L60-E
Table 2:	DTC P0758 2-3 Shift Solenoid Valve (2-3 SS Valve) -- Electrical

Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The 2-3 Shift Solenoid Valve (2-3 SS Valve) controls the fluid flow acting on the 2-3 shift valves. The solenoid is a normally-open exhaust valve. With the 1-2 Shift Solenoid Valve (1-2 SS Valve), the 2-3 SS Valve allows four different shifting combinations. The solenoid attaches to the control valve body within the transmission. The 2-3 SS Valve receives ignition voltage through circuit 1020. The VCM controls the solenoid by providing the ground path on circuit 1223.

When the VCM detects a continuous open or short to ground in the 2-3 SS Valve circuit or the 2-3 SS Valve, then DTC P0758 sets. DTC P0758 is a type A DTC.

Conditions for Setting the DTC

•	The system voltage is 10-19 volts.

•	The engine speed is greater than 450 RPM for 8 seconds.

•	Not in fuel cutoff.

•	All of the above conditions are met for 5 seconds and either of the following fail conditions occurs for 5 seconds:

-	The VCM commands the solenoid ON and the voltage remains high (B+).

-	The VCM commands the solenoid OFF and the voltage remains low (0 volts).

Action Taken When the DTC Sets

•	The VCM commands third gear only.

•	The VCM commands maximum line pressure.

•	The VCM freezes shift adapts from being updated.

•	The VCM inhibits TCC engagement.

•	The VCM illuminates the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the MIL/DTC

•	The VCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.

•	A scan tool can clear the DTC from the VCM history. The VCM clears the DTC from the VCM history if the vehicle completes 40 warm-up cycles without a failure reported.

•	The VCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the VCM.

Diagnostic Aids

•	Inspect the wiring for poor electrical connections at the VCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following conditions:

-	A bent terminal

-	A backed out terminal

-	A damaged terminal

-	Poor terminal tension

-	A chafed wire

-	A broken wire inside the insulation

•	When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

Shift Solenoid Valve State and Gear Ratio 4L60-E

Gear	1-2 Shift Solenoid	2-3 Shift Solenoid	Gear Ratio
1	ON	ON	3.059:1
2	OFF	ON	1.625:1
3	OFF	OFF	1.000:1
4	ON	OFF	0.696:1

Test Description

The numbers below refer to the step numbers on the diagnostic table.

This step tests the function of the 2-3 SS Valve and the Automatic Transmission Wiring Harness Assembly.

This step tests for power to the 2-3 SS Valve from the ignition through the fuse.

This step tests the ability of the VCM and of the wiring to control the ground circuit.

This step measures the resistance of the Automatic Transmission Wiring Harness Assembly and of the 2-3 SS Valve.

DTC P0758 2-3 Shift Solenoid Valve (2-3 SS Valve) -- Electrical

Step

Action

Value(s)

Yes

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Install the Scan Tool ®.
With the engine OFF, turn the ignition switch to the RUN position.

Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data.

Record the DTC Freeze Frame and Failure Records.

Were DTCs , P0753, P1860, P0740, and P0785 also set?

Go to Step 3

Go to Step 4

Inspect the TRANS fuse.
If the fuse is open, inspect the following components for a short to ground.

Refer to Electrical Diagnosis, Section 8.

•	Circuit 1020

•	The solenoid

•	The Automatic Transmission Wiring Harness Assembly

Repair the circuit, the solenoid, and the harness if necessary.

Did you find and correct a problem?

Go to Step 16

Command the 2-3 SS Valve ON and OFF three times while listening to the bottom of the transmission pan (a stethoscope may be necessary).

Did the solenoid click when commanded?

Go to Diagnostic Aids

Go to Step 5

Turn the ignition OFF.
Disconnect the transmission 20-way connector (additional DTCs will set).
Install the J 39775 Jumper Harness on the engine harness connector .
With the engine OFF, turn the ignition switch to the RUN position.
Connect a test lamp from J 39775 Jumper Harness cavity E to ground.

Is the test lamp ON?

Go to Step 7

Go to Step 6

Repair the open or short to ground in ignition feed circuit 1020 to the 2-3 SS Valve.

Refer to Electrical Diagnosis, Section 8.

Did you find and correct a problem?

Go to Step 16

Install a test lamp between cavity E and cavity B of the J 39775 Jumper Harness.
Using the transmission output control function, command the 2-3 SS Valve ON and OFF three times.

Does the test lamp illuminate when you command the shift solenoid ON, and does the test lamp turn off when you command the shift solenoid OFF?

Go to Step 10

Go to Step 8