I3Canadian
New member
- Joined
- Feb 27, 2017
- Messages
- 4
I don't know if others have had REX issues like I have on my 2014 i3 but I thought it might help someone to share the story.
Symptoms
- Failure of REX to transition from start-up RPM to full RPM, thus not enough energy going into the battery to sustain highway speeds
- When battery was depleted and parked, returning to the car to leave I would find the SoC at 0.0% and forced to wait for the REX to charge the battery to 1.5% minimum before I could get the car to move.
- These symptoms were initially intermittent and then became consistant with every drive in the fall of 2016.
Fix
The car was at the dealer from early November until Dec. 27, 2016
- There were multiple items replaced: Defective cell module #1; Replaced SME control unit; Replaced all eight CSC modules
After picking up the car and driving it three times the RPM issue returned and it went back to the delaer from Jan. 9-17, 2017.
- The technician performed a "REME" procedure which is the removal of the temperature sensor from the REX, running the REX for up to three hours with the sensor removed (to eliminate the possibility of moisture).
The car has worked perfectly since.
Summary
I believe the issue was rooted in a few things:
1. Failure of battery cell #1 which the car did not identify as a fault. As a result, the SoC was actually less than what appeared on the instrumentation.
2. Possible bad control modules which did not correctly identify the battery fault
3. Moisture in the REX temperature sensor which is designed to signal the REX that it is safe for the engine to move from startup RPM to high RPM when needed. If that sensor doesn't work correctly the REX will not adavance the RPM in a timely manner or at all.
I hope my learning experience may be of value to some other i3 drivers.
Alan
Symptoms
- Failure of REX to transition from start-up RPM to full RPM, thus not enough energy going into the battery to sustain highway speeds
- When battery was depleted and parked, returning to the car to leave I would find the SoC at 0.0% and forced to wait for the REX to charge the battery to 1.5% minimum before I could get the car to move.
- These symptoms were initially intermittent and then became consistant with every drive in the fall of 2016.
Fix
The car was at the dealer from early November until Dec. 27, 2016
- There were multiple items replaced: Defective cell module #1; Replaced SME control unit; Replaced all eight CSC modules
After picking up the car and driving it three times the RPM issue returned and it went back to the delaer from Jan. 9-17, 2017.
- The technician performed a "REME" procedure which is the removal of the temperature sensor from the REX, running the REX for up to three hours with the sensor removed (to eliminate the possibility of moisture).
The car has worked perfectly since.
Summary
I believe the issue was rooted in a few things:
1. Failure of battery cell #1 which the car did not identify as a fault. As a result, the SoC was actually less than what appeared on the instrumentation.
2. Possible bad control modules which did not correctly identify the battery fault
3. Moisture in the REX temperature sensor which is designed to signal the REX that it is safe for the engine to move from startup RPM to high RPM when needed. If that sensor doesn't work correctly the REX will not adavance the RPM in a timely manner or at all.
I hope my learning experience may be of value to some other i3 drivers.
Alan