VEHICLE CANNOT ACCELERATE FROM STANDSTILL, POOR ACCELERATION, INSUFFICIENT POWER

id300300000300

Outline

Malfunction symptom	Vehicle cannot accelerate from standstill, poor acceleration, insufficient power
Description	•  The vehicle cannot accelerate/reverse from a standstill even if the accelerator pedal is depressed with the selector lever in the D or R position. ―  Driving force is not generated and the vehicle cannot accelerate from a standstill. ―  Driving force is generated but the vehicle cannot accelerate from a standstill. •  Poor acceleration, insufficient power ―  Acceleration performance and constant speed according to the acceleration pedal operation are not possible.
Possible cause	Driving force is not generated and the vehicle cannot accelerate from standstill: •  PCM recognizes that accelerator pedal is not depressed ―  Accelerator pedal position sensor malfunction •  PCM recognizes that brake pedal is depressed ―  Brake switch malfunction ―  Malfunction in wiring harness or connector between brake switch and PCM •  PCM recognizes that selector lever is in position other than D or R ―  Selector lever malfunction •  PCM restricts output based on signal from drive motor control module ―  Fail-safe due to drive motor control module-related DTC detection •  PCM restricts output based on signal from BECM ―  Fail-safe due to BECM-related DTC detection ―  High voltage battery structural part malfunction ―  High voltage battery temperature is high or low ―  High voltage battery state of charge (SOC) decreased •  Fail-safe due to PCM-related DTC detection ―  EV system malfunction •  EV transaxle internal malfunction Driving force is generated but the vehicle cannot accelerate from standstill: •  Brakes are operating ―  Brake drag ―  Electric parking brake system malfunction •  Brake signal is input to electronically controlled brake unit •  Parking lock is operating ―  Parking lock system malfunction Poor acceleration, insufficient power: •  PCM falsely recognizes accelerator pedal depression amount ―  Accelerator pedal position sensor malfunction •  PCM recognizes that brake pedal is depressed ―  Brake switch malfunction ―  Malfunction in wiring harness or connector between brake switch and PCM •  PCM receives torque down request from electronically controlled brake unit ―  Electronically controlled brake system malfunction •  Brake signal is input to electronically controlled brake unit ―  Brake switch malfunction •  PCM restricts output based on signal from drive motor control module ―  Fail-safe due to drive motor control module-related DTC detection ―  Excessive temperature increase in electric motor or inverter (Output restriction operates while driving under heavy load such as when driving over a bump or curb) •  PCM restricts output based on signal from BECM ―  Fail-safe due to BECM-related DTC detection ―  High voltage battery structural part malfunction ―  High voltage battery temperature is high or low ―  High voltage battery state of charge (SOC) decreased •  Fail-safe due to PCM-related DTC detection ―  EV system malfunction •  Output restriction/brake command due to i-ACTIVSENSE operation •  Brakes are operating ―  Brake drag ―  Electric parking brake system malfunction •  Sliding resistance in EV transaxle is large
System wiring diagram	•  Not applicable
Connector diagram	•  Not applicable

Diagnostic Procedure

Step	Inspection	Results	Action
1	VERIFY DTCs •  Perform the DTC inspections for the following modules. (See DTC INSPECTION.) ―  PCM ―  BECM ―  Drive motor control module ―  Electronically controlled brake unit ―  Selector lever ―  Parking lock actuator •  Are DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (e-SKYACTIV)].) (See DTC TABLE [BECM (e-SKYACTIV)].) (See DTC TABLE [DRIVE MOTOR CONTROL MODULE (e-SKYACTIV)].) (See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].) (See DTC TABLE [SELECTOR LEVER].) (See DTC TABLE [PARKING LOCK ACTUATOR].)
		No	Go to the next step.
2	ELECTRIC MOTOR TORQUE RESTRICTION OF DRIVE MOTOR CONTROL MODULE •  Connect the M-MDS to the DLC-2. •  Switch the main power ON (READY off). •  Activate the M-MDS and perform the following procedure. 1.  Press [Start] to start the vehicle identification. 2.  Press the [Toolbox] tab. 3.  Press the [Diagnosis] icon. 4.  Press [Operational records]. 5.  Press [EV]. 6.  Press [Run] for [Reading records of Electric Motor torque restriction]. •  Display the electric motor torque restriction records according to the directions on the M-MDS screen. •  Do the electric motor torque restriction records display and the customer-stated symptoms match the driving condition that occurred?	Yes	Explain to the customer the cause of the occurrence with regard to the electric motor torque restriction records showing a match on the [Reading records of Electric Motor torque restriction] display with the driving conditions under which the customer-stated symptoms occurred.
		No	Driving force is generated but vehicle cannot accelerate from standstill: •  Go to the next step. Driving force is not generated and vehicle cannot accelerate from standstill, poor acceleration, and insufficient power: •  Go to Step 4.
3	INSPECT PARKING LOCK SYSTEM FOR MALFUNCTION •  Shift the selector lever to the D or R position. •  Is the parking lock released?	Yes	Go to the next step.
		No	Perform malfunction diagnosis according to the symptom troubleshooting for the parking lock system. (See SYMPTOM TROUBLESHOOTING [SHIFT-BY-WIRE SYSTEM].)
4	INSPECT ACCELERATOR PEDAL POSITION SENSOR FOR MALFUNCTION •  Inspect the applicable part. (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION.) •  Is the part normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See ACCELERATOR PEDAL REMOVAL/INSTALLATION.)
5	INSPECT BRAKE SWITCH FOR MALFUNCTION •  Inspect the applicable part. (See BRAKE SWITCH INSPECTION.) •  Is the part normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See BRAKE PEDAL REMOVAL/INSTALLATION [L.H.D.].) (See BRAKE PEDAL REMOVAL/INSTALLATION [R.H.D.].)
6	INSPECT HIGH VOLTAGE BATTERY COOLING SYSTEM FOR MALFUNCTION •  Perform symptom troubleshooting [HIGH VOLTAGE BATTERY DOES NOT COOL]. (See HIGH VOLTAGE BATTERY DOES NOT COOL.) •  Is the troubleshooting result normal?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification.
		No	Go to the next step.
7	INSPECT BATTERY HEATER FOR MALFUNCTION •  Perform symptom troubleshooting [HIGH VOLTAGE BATTERY DOES NOT WARM UP]. (See HIGH VOLTAGE BATTERY DOES NOT WARM UP.) •  Is the troubleshooting result normal?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification.
		No	Go to the next step.
8	VERIFY VEHICLE CONDITION Warning •  Observe legal speed limits when driving the vehicle and perform the procedure in a location where safety can be assured. Note •  Because the vehicle malfunction cannot be verified, it is necessary to inspect the items which may be affecting the running resistance. •  Perform the following inspections. ―  Brake drag ―  Electric parking brake system malfunction ―  Sliding resistance in EV transaxle (compare deceleration feel and free running distance in N position with another vehicle of same model, tire pressure and vehicle weight) •  Are all the items normal?	Yes	Explain to the customer that the output restriction is performed when the vehicle detects the following. •  High voltage battery temperature is high or low •  High voltage battery state of charge (SOC) decreased •  i-ACTIVSENSE system operation
		No	Repair or adjust the malfunctioning location and explain the repair contents to the customer based on the inspection result.
Repair completion verification	VERIFY THAT VEHICLE IS REPAIRED •  Install/connect the part removed/disconnected during the troubleshooting procedure. •  Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. (Explain contents of repair to customer.)
		No	Refer to the CAN (controller area network) malfunction diagnosis flow to inspect for a CAN communication error.   (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [L.H.D. (E)] .) (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [R.H.D.] .)