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U1428 on 2017-2026 Chrysler Pacifica Hybrid: Causes and Fixes for Implausible Torque Data

Code U1428 on a Pacifica Hybrid means the transmission controller received illogical data from the engine controller, causing limp mode. The most common causes are a weak 12V battery or outdated control module software. A dealer software update often fixes it. However, it can also be linked to serious underlying hardware issues covered by recalls, such as internal transmission wiring shorts.

21 minutes to read 2017-2026 Chrysler Pacifica Hybrid

Most Likely Cause

Outdated Control Module Software

Est. Time

2.5 hrs

DIY Doable?

🔧 Shop

Shop Labor

$150 – $800

Parts Price

$0 – $400

🚫 Do not drive — Driving is not recommended. The vehicle can suddenly enter 'limp mode,' causing a severe loss of power that is dangerous in traffic. In some cases, the underlying issue can lead to a complete and unexpected engine shutdown.

Key Takeaways

U1428 is a serious communication code that will put your Pacifica Hybrid in limp mode, making it unsafe to drive.
The most likely and easiest fixes are checking the 12V battery and ensuring all control module software is updated by a dealer.
This code is often a symptom of a major underlying hardware problem (internal transmission wiring) that is the subject of a major safety recall (23V-010).
Do not ignore this code. Immediately contact a Chrysler dealer with your VIN to check for open recalls and TSBs.

The trouble code U1428 is a manufacturer-specific code that, on a Chrysler Pacifica Hybrid, means 'Implausible Data Received' or more specifically, 'Inaccurate Engine Torque Received'. This is a network communication error. It indicates that the Transmission Control Module (TCM) has received data from the Powertrain Control Module (PCM) that it considers illogical or nonsensical. Because the TCM relies on accurate engine torque data to manage the complex interplay between the gas engine and electric motors for shifting, it triggers this fault as a safety measure, often forcing the vehicle into a limited-power 'limp mode'.

What's Unique About the 2017-2026 Chrysler Pacifica Hybrid

On the Pacifica Hybrid, this network code must be viewed in the context of its complex Plug-in Hybrid Electric Vehicle (PHEV) system. While software glitches and weak batteries are common causes on many Chrysler products, the Pacifica Hybrid has known issues with its Power Inverter Module (PIM) and internal transmission wiring harnesses. Recalls and Technical Service Bulletins (TSBs) have been issued for wiring that can chafe and short out inside the eFlite transmission, causing a variety of communication failures, sudden engine shutdowns, and system warnings. Therefore, a U1428 code on this vehicle warrants a closer look at potential hardware and wiring issues specific to the hybrid drivetrain, many of which are addressed by Safety Recall 23V-010 (03A).

Professional service recommended: Diagnosing this code requires professional scan tools (wiTECH) to check for software updates and inspect hybrid system components. The high-voltage system presents a safety risk for DIY diagnosis. Many of the root causes are linked to recalls or TSBs that must be performed by a dealer.

Symptoms You May Notice

Vehicle enters 'limp mode,' limiting speed to around 35-40 mph.
Check Engine Light is on.
'Service Hybrid System' or 'Propulsion System Warning' message may appear on the dash.
Sudden loss of acceleration and power.
Transmission may feel stuck in one gear or exhibit harsh shifting.
Vehicle may get stuck in Park or have no throttle response.
PRNDL lights on the dash and shifter knob may blink.

⚠️ Don't Waste Money on the Wrong Fix

Replacing the entire transmission. This is a communication code, not necessarily a sign of mechanical transmission failure, although it can be caused by an internal wiring fault that may lead to transmission replacement under warranty.
Replacing the throttle body. While throttle issues can cause limp mode, they typically set different, specific codes.

Most Likely Causes

Outdated Control Module Software 🔴 High Probability Software logic errors are a common issue across many modern vehicles, and FCA has released numerous software updates to address communication faults between modules. Specific recalls, like 23V-010, involve updating the PIM, IPC, and PCM software to manage hardware-related faults.
How to confirm: A dealer or a qualified shop with a wiTECH scan tool must check the current software versions for the PCM, TCM, and Hybrid Control Processor (HCP)/Power Inverter Module (PIM) against the latest available versions.
Typical fix: Reprogramming (flashing) the relevant control module(s) with the latest software. This is a dealer or specialty shop repair, often performed as part of a recall.
Est. part cost: $0
Weak or Failing 12V Battery 🟡 Medium Probability Modern vehicles are packed with sensitive electronics. Low system voltage during startup or from a failing battery can cause temporary communication glitches between modules, triggering network codes like U1428. The hybrid's 12V battery is located in the passenger compartment and must be an AGM type.
How to confirm: Perform a professional load test on the 12V battery. A simple voltage check is not sufficient; it must be tested under load. This can often be done for free at auto parts stores.
Typical fix: Replace the 12V AGM battery. 🎬 Watch: How to replace the 12V AGM battery
Est. part cost: $150-$350
Internal Transmission Wiring Harness Fault 🟡 Medium Probability The Pacifica Hybrid has a well-documented defect where an internal transmission wiring connector can short circuit, leading to unexpected engine shutdown. This is the primary subject of NHTSA recall 23V-010.
How to confirm: This requires extensive diagnosis by a dealer. They will check the vehicle's VIN for recall 23V-010 (Chrysler recall 03A) or TSB 21-025-25 REV. A. Diagnosis may require transmission disassembly to inspect the harness, which is often done only after the software recall fix fails to resolve the issue.
Typical fix: The initial fix per recall 23V-010 is a software update to warn the driver of impending shutdown. If the problem persists or is diagnosed as a hardware failure, the fix may involve replacing the transmission assembly, which may be covered under an extended warranty (XE1).
Est. part cost: $50-$500 (harness only, labor is significant)

Rare But Worth Checking

Failing Power Inverter Module (PIM): The PIM can fail due to internal issues, such as diode failure addressed in recall T34 (NHTSA 17V-371) for 2017-2018 models. A PIM failure can cause a sudden loss of power and trigger various hybrid system warnings and communication codes. This is a high-cost repair and should be considered after software and wiring are checked.
Failing Control Module (PCM or TCM): While rare, it's possible for one of the control modules to fail internally. This should only be considered after all software, battery, and wiring issues have been definitively ruled out.

Diagnosis Steps

Scan the vehicle for all Diagnostic Trouble Codes (DTCs) in all modules, not just the PCM. Note any other codes present, especially P1DD2.
Have the 12V battery professionally load tested. Do not skip this step. A weak 12V battery is a known cause of electronic issues on these vans. Replace if it fails the test.
If the battery is good, contact a Chrysler dealer with your VIN. Ask them to check for open recalls, especially 23V-010 (03A) for engine shutdown/wiring, and any TSBs related to software updates.
Have the dealer or a qualified shop perform any available software updates for the Powertrain Control Module (PCM), Transmission Control Module (TCM), and Power Inverter Module (PIM).
If software updates do not resolve the issue, diagnosis must proceed to the physical wiring. This is the point where professional help is essential.
The dealer should follow the diagnostic path for recall 23V-010 and TSB 21-025-25 REV. A, which may involve inspecting the internal transmission wiring harness for chafing or shorts.
If no wiring faults are found, the Power Inverter Module (PIM) should be tested, as it is another known point of failure causing similar symptoms.

Parts You'll Likely Need

12V AGM Battery (OEM #BB0H7730AB (superseded by BBH7F001AA)) — A weak 12V battery is a very common cause of network communication faults on modern Chrysler vehicles. It must be an AGM type because it is located inside the passenger compartment.
Trusted brands: Mopar, Interstate, DieHard, Duralast, EverStart
OEM price range: $250-$400
Aftermarket price range: $150-$350

Related Codes That Often Appear With This One

P1DD2 — P1DD2 means 'Torque Request Signal From TCM Denied'. This code is often set alongside U1428, as it directly relates to the TCM rejecting the torque signal it's receiving from the PCM. TSB 18-091-19 for other FCA vehicles confirms that these two codes frequently appear together and are often resolved with a PCM software update.
U0401 — This code means 'Invalid Data Received From ECM/PCM'. It is a more generic version of U1428 and points to the same communication breakdown between the engine and another module, often appearing in conjunction with P1DD2.

Technical Service Bulletins (TSBs) & Recalls

TSB #18-091-19: While for a 2018 Jeep Compass, it specifically addresses U1428 and P1DD2 being fixed by a PCM software update, highlighting the common nature of this fix on FCA platforms.
TSB 21-025-25 REV. A: 🎬 Watch: Pacifica Hybrid transmission symptoms and fixes Addresses internal transmission wiring connector shorts and motor bearing failures in 2017-2023 Pacifica Hybrids, which can cause communication issues and limp mode.
NHTSA Recall 23V-010 (FCA Campaign 03A): A critical safety recall for 2017-2023 models to address unexpected engine shutdown caused by an internal transmission wiring short. The remedy involves software updates and potentially a transmission replacement under an extended warranty (XE1).

Platform-Specific Known Issues

Chrysler has issued a major recall (NHTSA 23V-010 / FCA 03A) for 2017-2023 Pacifica Hybrids concerning an internal transmission wiring connector that can short out, causing an unexpected engine shutdown. This fault is directly related to the symptoms and codes seen with U1428.
Software glitches between the various control modules (PCM, TCM, PIM) are a common source of faults and are often resolved with a dealer-installed software update, many of which are part of a recall.
The eFlite transmission is also subject to TSB 21-025-25 REV. A for issues with motor bearings and position sensors, which can cause limp mode and other drivability problems.

Mechanic-Grade Diagnostic Values

CAN Bus Network Resistance — expected: ~60 Ω. Failure: A reading of ~120 Ω indicates an open in the circuit or a missing terminating resistor in one of the main control modules. A reading near 0 Ω indicates a short between the CAN High and CAN Low wires.
CAN High Voltage to Ground — expected: ~2.6V (average). Failure: Significant deviation from this voltage indicates a fault on the CAN High line. The voltage should fluctuate rapidly between 2.5V and 3.5V on an oscilloscope.
CAN Low Voltage to Ground — expected: ~2.4V (average). Failure: Significant deviation from this voltage indicates a fault on the CAN Low line. The voltage should fluctuate rapidly between 2.5V and 1.5V on an oscilloscope.
Module Flashing Battery Voltage — expected: 13.2V - 13.5V. Failure: Voltage dropping below 13.2V or climbing above 13.5V during a software flash can cause the procedure to fail or corrupt the module.

Scan Tool Commands That Help

wiTECH 2.0: Flash ECU / Reprogram Module — This is the primary function used by dealers to apply software updates to the PCM, TCM, PIM, and IPC as mandated by recalls like 23V-010 and various TSBs. It is often the first and only step needed to resolve U1428.
wiTECH 2.0: View Topology — This function displays all control modules on the vehicle's network and their communication status in a graphical layout. A module that is offline or has communication errors will be highlighted, helping to quickly isolate the source of a network fault like U1428.
wiTECH 2.0: Clear All DTCs — After performing a software flash or a physical repair, this function is used to clear fault codes from all modules simultaneously. This is a required step after any reprogramming.

Wiring & Ground Locations

G102 / G103 — Located in the engine compartment, typically on the cowl or shock tower on the driver's side.. These are primary engine and chassis ground points. Corrosion or looseness at these locations can create floating grounds, causing unpredictable behavior and communication errors between the PCM and other modules.
G201 / G202 — Located behind the instrument panel on the driver's side, often attached to the dash support structure.. These grounds are critical for the Body Control Module (BCM), Instrument Panel Cluster (IPC), and Data Link Connector (DLC). A fault here can disrupt network communication and cause a host of seemingly unrelated electrical issues.
Internal Transmission Harness Connector — Inside the eFlite SI-EVT transmission assembly.. This specific connector is the subject of NHTSA recall 23V-010. It is known to short circuit, causing a direct loss of communication and motive power, which can manifest as code U1428 and related symptoms.

Model Year Variations Within This Range

2017-2018: The software update for recall 23V-010 requires flashing the Power Inverter Module (PIM), Instrument Panel Cluster (IPC), and Powertrain Control Module (PCM).
2019-2023: The software update for recall 23V-010 only requires flashing the Power Inverter Module (PIM).

Diagnostic Flowchart

U1428 indicates a communication or data validity fault often linked to the hybrid powertrain. Begin by scanning all modules (PCM, TCM, PIM) to see if this is a standalone network glitch or a symptom of a hardware failure.

Check the VIN for NHTSA Recall 23V-010 (FCA 03A) or TSB 21-025-25 REV. A. Is the vehicle eligible for these updates?

→ Take the vehicle to a Chrysler dealer. The fix involves a critical software update for the PIM, PCM, and IPC to prevent unexpected engine shutdown and manage internal transmission wiring shorts.

Using a wiTECH tool, compare the current software versions of the PCM, TCM, and Power Inverter Module (PIM) to the latest FCA releases. Are they outdated?

→ Flash the PCM, TCM, and PIM with the latest software. Many U1428 instances are resolved by improving the handshake logic between these modules as noted in TSB 18-091-19.

Does the vehicle exhibit 'Limp Mode' (max 40mph) or blinking PRNDL lights on the shifter?

Inspect the internal transmission wiring connector for signs of short-circuiting or chafing (per TSB 21-025-25). Is damage found?

→ The internal harness has shorted. This may require a transmission assembly replacement. Check if the vehicle is covered under the XE1 extended warranty associated with the 03A recall.

→ If software is current and wiring is intact, the fault likely lies within the Power Inverter Module (PIM) hardware. Proceed with PIM diagnostic testing or replacement.

→ Inspect the high-voltage and low-voltage connectors at the PIM for corrosion or loose pins. If clean, monitor for recurrence as the issue may be an internal PIM logic fault.

Perform a professional load test on the 12V AGM battery (located in the rear cargo area). Does it pass the load test?

→ Replace the 12V AGM battery. Low system voltage during startup on the Pacifica Hybrid platform frequently triggers false U-series communication codes.