DESCRIPTION
The electronic throttle control system has a dedicated power supply circuit. The voltage (+BM) is monitored and when it is low (less than 4 V), the ECM determines that there is a malfunction in the electronic throttle control system and cuts off the current to the throttle actuator.
When the voltage becomes unstable, the electronic throttle control system itself becomes unstable. For this reason, when the voltage is low, the current to the throttle actuator is cut. If repairs are made and the system returns to normal, turn the engine switch off. On the next restart, the ECM will allow the current to flow to the throttle actuator.
Tech Tips
This electronic throttle control system does not use a throttle cable.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2118 | Open in electronic throttle control system power source (+BM) circuit (1 trip detection logic) |
|
FAIL-SAFE
When either of these DTCs, or other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions are stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator and the throttle valve is returned to a 6° throttle angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing in accordance with the accelerator pedal position to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.
The ECM continues operating in fail-safe mode until a pass condition is detected, and the engine switch is then turned off.
WIRING DIAGRAM
INSPECTION PROCEDURE
Note
Inspect the fuse for circuits related to this system before performing the following inspection procedure.
Tech Tips
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
READ VALUE USING INTELLIGENT TESTER (+BM VOLTAGE)
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / All Data / +BM Voltage.
Read the value displayed on the tester.
| Result | Proceed to |
|---|---|
| Below 11 V or higher than 14 V | A |
| 11 to 14 V | B |
| B |
|
CHECK FOR INTERMITTENT PROBLEMS Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (BATTERY - ECM, ECM - BODY GROUND)
Disconnect the ECM connectors.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Open) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the ECM connectors.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE ECM Click here