You are having a tranny valving problem solve that and it may get rid of the misfire issue. It would be best to leave it to a tranny shop if you do not have the proper scanner.
4L60-E / 4L65-E Automatic Transmission
Diagnostic Chart (Part 1 Of 3)
Diagnostic Chart (Part 2 Of 3)
Diagnostic Chart (Part 3 Of 3)
Schematic
CIRCUIT DESCRIPTION
The 1-2 Shift Solenoid
(SS) valve controls the fluid flow acting on the 1-2 and 3-4 shift valves. The solenoid is a normally-open exhaust valve. With the 2-3 SS valve, the 1-2 SS valve allows four different shifting combinations. The solenoid attaches to the control valve body within the transmission. The 1-2 SS valve receives ignition voltage through circuit 1020. The Vehicle Control Module
(VCM) controls the solenoid by providing the ground path on circuit 1222.
When the VCM detects a continuous open, short to ground, or short to power in the 1-2 SS valve circuit, then DTC P0753 sets. DTC P0753 is a type A DTC.
CONDITIONS FOR RUNNING THE DTC
- The system voltage is 10-19 volts.
- The engine speed is greater than 450 RPM for 5 seconds .
- The engine is not in fuel cutoff.
CONDITIONS FOR SETTING THE DTC
DTC P0753 sets if one of the following conditions occurs for
5 seconds:
Condition 1
The VCM commands the solenoid ON and the voltage feedback remains high (B+).
Condition 2
The VCM commands the solenoid OFF and the voltage feedback remains low
(0 volts) .
ACTION TAKEN WHEN THE DTC SETS
- The VCM illuminates the Malfunction Indicator Lamp (MIL) .
- The VCM commands D2 line pressure.
- The VCM inhibits 3-2 downshifts if the vehicle speed is greater than 48 km/h (30 mph) .
- The VCM freezes shift adapts from being updated.
- The VCM records the operating conditions when the Conditions for Setting the DTC are met. The VCM stores this information as Freeze Frame and Failure Records.
- The VCM stores DTC P0753 in VCM history.
CONDITIONS FOR CLEARING THE MIL/DTC
- The VCM turns OFF the MIL during the third consecutive trip in which the diagnostic lest runs and passes.
- A scan tool can clear the MIL/DTC.
- The VCM clears the DTC from VCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
- The VCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the VCM.
DIAGNOSTIC AIDS
- Inspect the wiring at the VCM, the transmission connector and all other circuit connecting points for the following conditions:
- A backed out terminal
- A damaged terminal
- Reduced terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
- When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.
- Refer to the Shift Solenoid Valve State and Gear Ratio table.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
- This step tests the function of the 1-2 SS valve and the Automatic Transmission (AT) wiring harness assembly.
- This step tests for power to the 1-2 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 IAT wiring harness assembly and of the 1-2 SS valve.
---------- Post added at 02:32 PM ---------- Previous post was at 02:30 PM ----------
stock replacements should be Ac delco or Delphi.
