# Service bulletin 18\-057\-16

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 10181480
- Published by NHTSA: 2020\-10\-26
- Manufacturer's number: 18\-057\-16
- Manufacturer's date: 2016\-05\-11
- NHTSA component: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\); ELECTRICAL SYSTEM

## NHTSA's summary

Flash: 3.6L Powertrain Diagnostic And System Enhancements This bulletin involves reprogramming the Powertrain Control Module \(PCM\) with the latest available software. A small number of customers may experience a Malfunction Indicator Lamp \(MIL\) illumination and/or one of the following conditions. Upon further investigation, a technician may find the following Diagnostic Trouble Code \(DTC\) stored in the Anti\-lock Brake System \(ABS\) Module memory: NOTE: The Diagnostic Trouble Code \(DTC\) is caused by a calibration in the PCM that is in conflict with the ABS Module programming. The new software flash will correct this issue. · C121C\-00 \- Torque Request Signal Denied.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2016/MC-10181480-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2016/MC-10181480-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Electrical system, Transmission and driveline, Automatic transmission, Transmission control module

## Trouble codes named

C121C

## Vehicles listed

- 2017 CHRYSLER PACIFICA

## Other bulletins for the same vehicles and component

- [1802023](/bulletins/10248032.md), 2024-01-02, Service bulletin: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\). Flash: Powertrain Control Module \(PCM\) Updates Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes \(DTCs\) have been set: ? P0335 \- Crankshaft Position Sensor Circuit \(NA Only\). ? P0339 \- Crankshaft Position Sensor Intermittent \(NA Only\). Major monitor \(misfire\) and other diagnostics are disabled on a pending DTCs P0335 and P0339.\*\* Software enhancement: Technicians and/or customers may report the vehicle will not pass a state smog check due to permanent fault codes which will not clear. As a result, the vehicles are not eligible to be registered in certain states. ? Corrections to allow the vehicle to clear the permanent fault codes. This bulletin involves reprogramming the PCM with the latest available software. NOTE: Four modules are required to be flashed for this update to be effective, the following modules are all to be updated along with this PCM update: ? Electronic Brake Booster Module \(EBBM\). ? AntiLock Brake System Module \(ABS\). ? Hybrid Control Processor \(HCP\) and Auxiliary Hybrid Control Processor \(AHCP\) or also known as a Power Inverter Module \(PIM\).
- [2102717](/bulletins/10223670.md), 2022-10-17, Service bulletin: POWER TRAIN; ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\). This bulletin involves reprogramming the Transmission Control Module \(TCM\) with the latest available software. Some customers may experience a Malfunction Indicator Lamp \(MIL\) illumination.
- [21\-018\-16](/bulletins/10141285.md), 2018-06-18, Service bulletin: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\); ELECTRICAL SYSTEM:IGNITION. Flash: Transmission Diagnostic And Shift Enhancements This bulletin involves reprogramming the Transmission Control Module \(TCM\) with the latest available software. A small number of customers may experience a Malfunction Indicator Lamp \(MIL\) illumination and/or one of the following conditions. Upon further investigation, a technician may find the following Diagnostic Trouble Code \(DTC\) stored in the TCM memory: · P1DDE\-00 \- Ignition Run/Start Input 1\-2 Correlation.
- [18\-057\-16](/bulletins/10141280.md), 2018-06-18, Service bulletin: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE \(TCM/PCM/TECM\); SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:ABS WARNING LIGHT; POWER TRAIN:AUTOMATIC TRANSMISSION:TORQUE CONVERTER. Flash: 3.6L Powertrain Diagnostic And System Enhancements This bulletin involves reprogramming the Powertrain Control Module \(PCM\) with the latest available software. A small number of customers may experience a Malfunction Indicator Lamp \(MIL\) illumination and/or one of the following conditions. Upon further investigation, a technician may find the following Diagnostic Trouble Code \(DTC\) stored in the Anti\-lock Brake System \(ABS\) Module memory: NOTE: The Diagnostic Trouble Code \(DTC\) is caused by a calibration in the PCM that is in conflict with the ABS Module programming. The new software flash will correct this issue. · C121C\-00 \- Torque Request Signal Denied.
- [9003730](/bulletins/10138854.md), 2018-06-04, Service bulletin: POWER TRAIN:AUTOMATIC TRANSMISSION. SI\-eVT Transmission \- China Variant The service SI\-eVT is shipped with a non\-China wiring harness \(68241331AC\). China market replacement must replace wiring harness with 68368596AA. The China variant 68368596AA wiring harness has an interlock to the electrical charge door.
- [21\-022\-16](/bulletins/10080072.md), 2016-09-14, Service bulletin: POWER TRAIN:AUTOMATIC TRANSMISSION. "FLASH: TRANSMISSION SHIFT AND DRIVABILITY ENHANCEMENTS THIS BULLETIN INVOLVES REPROGRAMMING THE TRANSMISSION CONTROL MODULE \(TCM\) WITH THE LATEST AVAILABLE SOFTWARE. SOME CUSTOMERS MAY EXPERIENCE A MALFUNCTION INDICATOR LAMP \(MIL\) ILLUMINATION. UPON FURTHER INVESTIGATION, A TECHNICIAN MAY FIND THE FOLLOWING DIAGNOSTIC TROUBLE CODE \(DTC\) STORED IN THE TCM MEMORY: · P1CC9 \- UNABLE TO ENGAGE GEAR."

JSON: [/v1/bulletins/10181480](/v1/bulletins/10181480)

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