What the P0882 code means
Since the mid 1980s, every vehicle with an automatic transmission has been designed with electronic shift controls. These computer controlled transmissions supply power to the transmission control module through a transmission control output circuit. A P0882 code means that low voltage is detected from the transmission control module circuit.
What causes a P0882 code?
Low voltage from the battery, or an open or shorted circuit in the transmission control circuit are common causes of a P0882 code.
What are the symptoms of a P0882 code?
- Stored code and illuminated Malfunction Indicator Lamp (MIL)
- Limp-in mode – transmission will not shift out of low gear
In some vehicles, the transmission may shift as designed and display no symptoms other than an illuminated MIL and stored code.
How does a mechanic diagnose a P0882 code?
Since the P0882 code is related to electronic shift control problems, a low voltage condition from the battery can be at fault. A technician should check to ensure that battery voltage is proper before going any farther with in-depth electronic diagnosis.
Telltale signs of a weak battery include slow or weak cranking and a frequent need for jump-starts to start the engine.
Load test the battery – many auto parts stores will perform load testing on batteries (out of vehicle) for no charge.
If the load test fails, replace the battery.
With the engine running, use your multimeter to check alternator output. A normal alternator should produce around 14.0 volts – if its output is less than 12.0 volts at any time while the engine is running, replace the alternator.
A starter that has an excessive voltage draw while cranking can cause erroneous codes in the PCM. Slow engine cranking or no-crank situations while the battery is fully charged can both be indicators. Test the starter’s current draw with your multimeter and replace if necessary, then retest for P0882 code.
Clear the DTC with a code reader and test drive the vehicle. If the code returns, move on with diagnosis.
Using a wiring diagram for the specific year/make/model, locate the transmission control circuit at the PCM connector.
With the key in “off” position, check the circuit between the PCM and powertrain control module/totally integrated power module.
This transmission control circuit should read 5.0 ohms. Any resistance reading of less than 5.0 ohms indicates a likely short to ground.
Locate the ground wire for the circuit and monitor the resistance while you wiggle the wire and check for any breaks or chafed sections. If the resistance fluctuates while wiggling a section, perform a repair on the wire. Clear the codes, test drive the vehicle and retest the system.
Check the transmission control circuit resistance in the same fashion. If resistance is more than 5.0 ohms, there’s likely an open circuit.
Check for breaks in the wiring along the length of the transmission control circuit. Repair any breaks in the wiring and make sure all connectors are in place.
Be mindful of any corrosion, bent or broken pins or evidence of moisture in connections. Repair any connection issues even if they are not related – they may still serve to provide power to the transmission control circuit.
If everything else checks as good, the fault might lie with the PCM but remember that failed PCMs are rare.
Common mistakes while diagnosing P0882 code
Too often, technicians go immediately to transmission problems and ignore loose connections, poor battery current or other related problems that can be causing a P0882 code. A careful process of elimination is necessary to properly diagnose and repair a P0882 code.
How serious is a P0882 code?
A P0882 code can result in a transmission that’s in limp-in mode, making the vehicle barely drivable.
What repairs can fix a P0882 code?
- Replacing battery
- Diagnosing and repairing open circuits or shorts in transmission control circuit
- Replacing alternator
- Replacing starter
- Repairing/replacing wiring in related circuits
Need help with a P0882 code?
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