Drive Motor 2 Control Module Hybrid/EV Battery Voltage System Isolation Lost
Table of contents
P1AF2 CHEVROLET Possible Causes
- Faulty Drive Motor 2 Control Module Hybrid/EV Battery
- Drive Motor 2 Control Module Hybrid/EV Battery harness is open or shorted
- Drive Motor 2 Control Module Hybrid/EV Battery circuit poor electrical connection
How do I fix code P1AF2 CHEVROLET?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- 2017 Malibu and Volt models. These models are equipped with the 5ET50 automatic transmission (RPOs MKV, MKE), which is an electronically-controlled, continuously-variable electric transmission (or drive unit) on hybrid models.
- The following DTCs may be set:
- – P1AEE – Drive Motor 1 Control Module Hybrid/EV Battery System Voltage High Voltage
- – P1AEF– Drive Motor 2 Control Module Hybrid/EV Battery System Voltage High Voltage
- – P1AF0 – Drive Motor 1 Control Module Hybrid/EV Battery Voltage System Isolation Lost
- – P1AF2 – Drive Motor 2 Control Module Hybrid/EV Battery Voltage System Isolation Lost
- – P1E22 – Auxiliary Transmission Fluid Pump Control Module Hybrid/EV Battery Voltage System Isolation Lost
- If only two or three of these DTCs are set, follow the appropriate Service Information diagnostic procedures. The cause may not be any internal components of the transmission.
- If all five DTCs are set, there is an internal fault with the transmission and the transmission requires replacement. Do not attempt any internal repairs.
Cost of diagnosing the P1AF2 CHEVROLET code
The cost of diagnosing the P1AF2 CHEVROLET code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1AF2 CHEVROLET Description
The power inverter module, often referred to as the drive motor generator power inverter module, contains three motor control modules and the hybrid powertrain control module. Two of the motor control modules operate their respective drive motor generator based upon power inverter module commands. The third motor control module controls the auxiliary transmission fluid pump motor. Each motor control module measures hybrid battery high voltage with several internal sensors. The motor control modules test for loss of isolation between either the high-voltage positive circuit or high-voltage negative circuit and vehicle chassis. The motor control modules test for isolation when the high-voltage contactor relays are closed. The hybrid powertrain control module 2 only tests the hybrid battery assembly for high-voltage loss of isolation when the high-voltage contactor relays are open.
Motor control modules’ loss of isolation is detected through the use of two high-impedance resistors and voltage measuring circuitry. The two resistors are connected in series between the high- voltage positive and high-voltage negative circuits. The centre connection of the two resistors is also connected to vehicle chassis. The motor control module then measures the voltage drop across one of the resistors. Without a loss of isolation, the motor control module should measure about half of the high voltage potential. This is referred to as mid-pack voltage. The Mid-pack voltage value is then doubled by the software and displayed on a scan tool as Motor 1 Isolation Voltage or Motor 2 Isolation Voltage. When a loss of isolation is present, the motor isolation voltage display will indicate voltage that is more or less than actual hybrid battery high voltage.