Reference meaning
What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
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A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Scan worksheet →Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P1634Output Speed Sensor-Wheel Speed Rationality
P1634MPI Module Signal Circuit Malfunction
P1634-00TCM Internal Watchdog Performance (ERB)
Manufacturer communications
9Original wording in English
ACURA
"Service Bulletin - The motor power inverter (MPI), also known as the intelligent inverter unit (IIU), may fail over time due to a defective solder joint. This failure may result in one or more of the following DTC(s): -P1440 (MPI Module Output Circuit Malfunction) -P1437 (MPI Module Short Circuit) -P15A5 (Motor Current Sensor C…
HONDA
"Service Bulletin - The Motor Power Inverter (MPI), also known as the Intelligent Inverter Unit (IIU), may fail over time due to a defective solder joint. This failure may result in one or more of the following DTC(s): -P1440 (MPI Module Output Circuit Malfunction) -P1437 (MPI Module Short Circuit) -P15A5 (Motor Current Sensor C…
RAM
Flash: Transmission Diagnostic and Shift Enhancements This bulletin involves reprogramming the Transmission Control Module (TCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following DTCs:P1634 …
RAM
Flash: Transmission Shift and Driveability Enhancements This bulletin involves reprogramming the Transmission Control Module (TCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following Diagnosti…
Check vehicle applicability
10A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Acura | ILX HYBRID ↗ | 2013 |
| Chrysler | 200 ↗ | 2015 |
| Honda | CIVIC HYBRID ↗ | 2015 |
| Honda | CIVIC HYBRID ↗ | 2014 |
| Honda | CIVIC HYBRID ↗ | 2013 |
| Honda | CIVIC HYBRID ↗ | 2012 |
| Jeep | CHEROKEE ↗ | 2015 |
| Jeep | GRAND CHEROKEE ↗ | 2015 |
Code meaning and manufacturer information
Original wording in English · Historical directory labels; manufacturer applicability has not been established for every entry.
Data Output Link Circuit Failure
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.