# Service bulletin 18\-074\-26

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: 11035324
- Published by NHTSA: 2026\-07\-29
- Manufacturer's number: 18\-074\-26
- Manufacturer's date: 2026\-07\-24
- NHTSA component: ENGINE; POWER TRAIN

## NHTSA's summary

Flash: Powertrain Control Module \(PCM\) Updates Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): ● P2AF6\-00 \- Starter Relay 3 Stuck Off \(with DBSM\). ● P014B\-00 \- O2 Sensor 2\-2 Delayed Response\-Lean To Rich. ● P062B\-00 \- Internal Control Module Fuel Injector Control Performance. Customers may also comment on the following: ● Engine Stop/Start \(ESS\) inoperative with "Auto Stop Start Not Ready" message in Instrument Panel Cluster \(IPC\). The following software enhancements are also available: ● Update to enable Exhaust Gas Recirculation \(EGR\) disable during gear shift for smoother shifting. ● Update for the Brake System Control Module \(BSCM\) MIL illumination request not setting the MIL on the Powertrain Control Module \(PCM\). This bulletin involves inspecting and possibly reprogramming the PCM with the latest available software.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2026/MC-11035324-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2026/MC-11035324-9999.pdf)

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

## Components

Engine, Transmission and driveline

## Trouble codes named

P014B, P062B, P2AF6

## Vehicles listed

- 2026 JEEP GRAND WAGONEER

## Other bulletins for the same vehicles and component

- [18\-074\-26 REV. A](/bulletins/11038535.md), 2026-10-16, Service bulletin: ENGINE. Flash: Powertrain Control Module \(PCM\) Updates Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): ● \*\*P013E\-00 \- O2 Sensor Delayed Response \- Rich to Lean Bank 1 Sensor 2. ● P014A\-00 \- O2 Sensor Delayed Response \- Rich to Lean Bank 2 Sensor 2. ● B1811\-00 \- Driver Door Ajar Input Circuit Low. ● B25C7\-00 \-Driver Door Ajar Switch 2 Circuit Low.\*\* ● P2AF6\-00 \- Starter Relay 3 Stuck Off \(with DBSM\). ● P014B\-00 \- O2 Sensor 2\-2 Delayed Response\-Lean To Rich. ● P062B\-00 \- Internal Control Module Fuel Injector Control Performance. Customers may also comment on the following: ● Electronic Start Stop \(ESS\) inoperative or "Auto Stop/Start Not Ready" message displayed in the Instrument Panel Cluster \(IPC\). NOTE: \*\*Normal Auto Stop/Start inhibit conditions should not be considered the cause of this concern. The condition is associated with DTC P2AF6.\*\* The following software enhancements are also available: ● \*\*Improvements to prevent misfire DTCs P0300\-P0306 that may set if one of the following DTCs set: ○ P0355\-00 \- Ignition Coil 5 Circuit. ○ P0336\-00 \- Crankshaft Position Sensor Performance.\*\* ● Update to enable Exhaust Gas Recirculation \(EGR\) disable during gear shift for smoother shifting. ● Update for the Brake System Control Module \(BSCM\) MIL illumination request not setting the MIL on the Powertrain Control Module \(PCM\). This bulletin involves inspecting and possibly reprogramming the PCM with the latest available software.
- [18\-074\-26 REV. A](/bulletins/11038498.md), 2026-10-16, Service bulletin: ENGINE. Flash: Powertrain Control Module \(PCM\) Updates Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): ● \*\*P013E\-00 \- O2 Sensor Delayed Response \- Rich to Lean Bank 1 Sensor 2. ● P014A\-00 \- O2 Sensor Delayed Response \- Rich to Lean Bank 2 Sensor 2. ● B1811\-00 \- Driver Door Ajar Input Circuit Low. ● B25C7\-00 \-Driver Door Ajar Switch 2 Circuit Low.\*\* ● P2AF6\-00 \- Starter Relay 3 Stuck Off \(with DBSM\). ● P014B\-00 \- O2 Sensor 2\-2 Delayed Response\-Lean To Rich. ● P062B\-00 \- Internal Control Module Fuel Injector Control Performance. Customers may also comment on the following: ● Electronic Start Stop \(ESS\) inoperative or "Auto Stop/Start Not Ready" message displayed in the Instrument Panel Cluster \(IPC\). NOTE: \*\*Normal Auto Stop/Start inhibit conditions should not be considered the cause of this concern. The condition is associated with DTC P2AF6.\*\* The following software enhancements are also available: ● \*\*Improvements to prevent misfire DTCs P0300\-P0306 that may set if one of the following DTCs set: ○ P0355\-00 \- Ignition Coil 5 Circuit. ○ P0336\-00 \- Crankshaft Position Sensor Performance.\*\* ● Update to enable Exhaust Gas Recirculation \(EGR\) disable during gear shift for smoother shifting. ● Update for the Brake System Control Module \(BSCM\) MIL illumination request not setting the MIL on the Powertrain Control Module \(PCM\). This bulletin involves inspecting and possibly reprogramming the PCM with the latest available software.
- [9100861 Rev 3](/bulletins/11035994.md), 2026-08-06, Service bulletin: ENGINE. PUMP, Auxiliary Coolant Before replacing the Auxiliary Coolant Pump, please perform the following steps: 1\) Key ON/OFF and let the after\-run pump run for at least 20 minutes before moving on to step \#2. 2\) Inspect the pump connector area for presence of water. 3\) Inspect the pump connector for corrosion. 4\) Inspect the pump for coolant contamination as this can cause the pump to stall. 5\) Inspect battery terminals for damage to rule out a battery drainage issue. 6\) Ensure the PCM is up\-to\-date with the latest available flash. If correct repair is not performed then the claim or condition will be recovered by Warranty Operations.
- [08\-289\-26 REV. A](/bulletins/11035971.md), 2026-08-06, Service bulletin: POWER TRAIN. Transmission Control Module \(TCM\) Diagnostic N/A \- This bulletin was released in error. SYMPTOM:
- [08\-289\-26](/bulletins/11035313.md), 2026-07-29, Service bulletin: ELECTRICAL SYSTEM; POWER TRAIN. Transmission Control Module \(TCM\) Diagnostic Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following DTCs: ● P2797\-00 \- Auxiliary Transmission Fluid Pump Performance ● P1625\-00 \- Park Pawl System Failure NOTE: Park system still functions, no impact to park engagement. NOTE: Vehicle will not experience unintended movement. Customers may also experience one or more of the following: ● Vehicle no start due to battery discharge. ● 'Start/stop inop' message. ● 'Service Transmission' message on in Instrument Panel Cluster \(IPC\).
- [9100861 Rev 1](/bulletins/11035194.md), 2026-07-23, Service bulletin: ENGINE. PUMP, Auxiliary Coolant Before replacing the Auxiliary Coolant Pump, please perform the following steps: 1\) Key ON/OFF and let the after\-run pump run for at least 20 minutes before moving on to step \#2. 2\) Inspect the pump connector area for presence of water. 3\) Inspect the pump connector for corrosion. 4\) Inspect the pump for coolant contamination as this can cause the pump to stall. 5\) Inspect battery terminals for damage to rule out a battery drainage issue. 6\) Ensure the PCM is up\-to\-date with the latest available flash.
- [9100861](/bulletins/11035070.md), 2026-07-18, Service bulletin: ENGINE; ELECTRICAL SYSTEM. PUMP, Auxiliary Coolant Before replacing the Auxiliary Coolant Pump, please perform the following steps: 1\) Key ON/OFF and let the after\-run pump run for at least 20 minutes before moving on to step \#2. 2\) Inspect the pump connector area for presence of water. 3\) Inspect the pump connector for corrosion. 4\) Inspect the pump for coolant contamination as this can cause the pump to stall. 5\) Ensure the PCM is up\-to\-date with the latest available flash. 6\) Inspect battery terminals for damage to rule out a battery drainage issue.
- [21\-053\-26](/bulletins/11034906.md), 2026-07-08, Service bulletin: POWER TRAIN. Service Transmission Message Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must SYMPTOM: exhibit/set the following Diagnostic Trouble Code \(DTC\): ● P2797\-00 \- Auxiliary Transmission Fluid Pump Performance. Customers may also comment on the following: ● Engine Stop\-Start \(ESS\) does not operate. ● "Service Transmission" message displayed in the Instrument Panel Cluster \(IPC\). This bulletin involves inspecting and possibly replacing the transmission oil pump motor.
- [09\-012\-26 REV. A](/bulletins/11034321.md), 2026-07-02, Service bulletin: ENGINE. Oil Pan Leak Customers may experience the following: SYMPTOM: ● 'Low Oil Level' message on in the Instrument Panel Cluster \(IPC\). ● Oil Leak. This bulletin involves replacing the engine oil pan.
- [09\-012\-26](/bulletins/11034320.md), 2026-07-02, Service bulletin: ENGINE. Oil Pan Leak Customers may experience the following: SYMPTOM: ● 'Low Oil Level' message on in the Instrument Panel Cluster \(IPC\). ● Oil Leak. This bulletin involves replacing the engine oil pan.

JSON: [/v1/bulletins/11035324](/v1/bulletins/11035324)

[Report an error on this page](https://github.com/wenmar-pro/wenmar-open/issues/new?template=data_correction.yml&title=Data%20correction%3A%20Service%20bulletin%2018-074-26&page=https%3A%2F%2Fopen.wenmarpro.com%2Fbulletins%2F11035324&vehicle=Service%20bulletin%2018-074-26)