A transmission solenoid pack is an assembly that combines several shift and pressure control solenoids, and often the pressure switches and a fluid temperature sensor, in one replaceable unit. Many Chrysler automatics, such as the 62TE, 545RFE and 68RFE, and Ford units such as the E4OD and 4R100 use one. When the pack fails, the transmission usually goes into limp mode, shifts harshly or stops shifting, and stores solenoid or pressure switch codes.
Bad solenoid pack symptoms
- Limp mode, often stuck in second gear on Chrysler RFE transmissions; see limp mode
- Harsh, delayed or missing shifts
- No converter lockup or shudder
- Check engine or transmission warning light with codes
Codes that point to a solenoid pack
| Code | Meaning |
|---|---|
| P0750 to P0766 | Shift solenoid circuit and performance faults |
| P0841, P0846 | Pressure switch faults |
| P0748 | Pressure control solenoid electrical |
| P0743 | Converter clutch solenoid electrical |
| P0882 | Low power supply to the transmission module |
Where is the solenoid pack?
It depends on the transmission. On some front-wheel-drive Chrysler transaxles such as the 62TE, the pack bolts to the outside of the case, which makes replacement straightforward. On many rear-wheel-drive units it sits on the valve body under the transmission pan, so the pan and filter come off first. Ford’s E4OD and 4R100 also carry their solenoid body inside the pan.
How to test a solenoid pack
- Check fluid level and condition first; dirty fluid makes solenoids stick.
- Check battery voltage and the transmission module power and grounds; low voltage mimics solenoid faults.
- Inspect the connector for corrosion, bent pins and fluid intrusion.
- Measure each solenoid’s resistance at the connector against the specification.
- Use a bidirectional scan tool to command solenoids and watch pressure switch responses.
Replacing a solenoid pack
Clean the mating surface, use the new gasket or seals supplied, torque the bolts to specification and refill to the correct level with the specified fluid. Chrysler transmissions need a quick learn procedure with a scan tool afterward so shifts are smooth; many others benefit from an adaptive reset.
Solenoid pack or valve body?
The solenoid pack is the electrical part that tells the hydraulics what to do; the valve body is the maze of passages and valves that routes the fluid. Electrical codes that point at one circuit, or a pack that fails a resistance test, suggest the pack. Shift problems with clean electrical tests, debris in the pan or worn valve bores suggest the valve body or internal wear. A shop can confirm with pressure tests before parts are replaced.
When a new pack does not fix it
If codes return or the transmission still slips, the cause is likely internal wear or valve body damage; see transmission solenoid symptoms, 68RFE problems and transmission rebuild vs replacement, and compare units on our 62TE, 545RFE, 68RFE, 4R100 and E4OD pages.
More guides: 545RFE problems · 62TE problems · E4OD problems · 4R100 problems · valve body problems.
Trouble codes: P0845 Trans Pressure Switch B Circuit · P0847 Trans Pressure Switch B Low · P0848 Trans Pressure Switch B High · P0870 Trans Pressure Switch C Circuit · P0871 Trans Pressure Switch C Range · P0873 Trans Pressure Switch C High · P0843 Trans Pressure Switch A High · all OBD2 codes.
Shipping is a flat $80.00 per order to US addresses, with 15-day free returns. Questions? Ask a parts specialist.