Toyota Yaris: Stop And Start System / Park/Neutral Switch Circuit Short to Ground (P085011,P085015)
DESCRIPTION
The engine stop and start ECU detects a malfunction by comparing the shift position signal with the neutral position switch signal input state. If a malfunction is detected, the engine stop and start ECU blinks the stop and start cancel indicator light, prohibits the stop and start control and stores DTC P085011 or P085015.
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory | Note |
P085011 | Park/Neutral Switch Circuit Short to Ground | The following condition continues for 1 second or more (1 trip detection logic) -
Short in neutral position switch circuit.
| -
Neutral position switch
-
Engine stop and start ECU
-
ECM
-
Wire harness or connector
| Blinking | DTC stored | SAE Code: P0851 |
P085015 | Park/Neutral Switch Circuit Short to Battery or Open | The following condition continues for 1 second or more (1 trip detection logic) -
Open or short in neutral position switch circuit.
| -
Neutral position switch
-
Engine stop and start ECU
-
ECM
-
Wire harness or connector
| Blinking | DTC stored | SAE Code: P0852 |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
-
Before replacing the engine stop and start ECU, read the number of starter operations and write it into a new engine stop and start ECU.
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-
After replacing the engine stop and start ECU, perform learning of the external backup boost converter (eco run vehicle converter assembly).
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-
After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.
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-
When the ECM is replaced on a vehicle with a non-specified auxiliary battery, it is necessary to perform auxiliary battery type switching.
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-
Inspect the fuses for circuits related to this system before performing the following procedure.
HINT:
-
Using the GTS, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.
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-
For wire harness and connector inspection procedures and precautions, refer to
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DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.
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PROCEDURE
1. | READ VALUE USING GTS (NEUTRAL SWITCH) |
Powertrain > Stop and Start > Data List
Tester Display |
Neutral Switch |
(a) Read the value when the shift lever is in neutral and any other position.
OK:
Tester Display | Condition | Normal Condition |
Neutral Switch | Shift lever in neutral | ON |
Neutral Switch | Shift lever in any position other than neutral | OFF |
OK |
| USE SIMULATION METHOD TO CHECK |
NG |
| |
2. | CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - NEUTRAL POSITION SWITCH) |
(a) Disconnect the A67 engine stop and start ECU connector.
(b) Disconnect the D44 neutral position switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
A67-26 (TMVC) - D44-1 (W1) | Always | Below 1 Ω |
A67-25 (TME2) - D44-3 (F+) | Always | Below 1 Ω |
A67-8 (TMN) - D44-2 (TMN) | Always | Below 1 Ω |
A67-26 (TMVC) - Body ground and other terminals | Always | 10 kΩ or higher |
D44-1 (W1) - Body ground and other terminals | Always | 10 kΩ or higher |
A67-25 (TME2) - Body ground and other terminals | Always | 10 kΩ or higher |
D44-3 (F+) - Body ground and other terminals | Always | 10 kΩ or higher |
A67-8 (TMN) - Body ground and other terminals | Always | 10 kΩ or higher |
D44-2 (TMN) - Body ground and other terminals | Always | 10 kΩ or higher |
NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
| |
3. | CHECK ENGINE STOP AND START ECU (TMN TERMINAL VOLTAGE) |
(a) Measure the voltage according to the value(s) in the table below.
*a | Component with harness connected (Engine Stop and Start ECU) | - | - |
Standard Voltage:
Tester Connection | Condition | Specified Condition |
A67-8 (TMN) - A67-25 (TME2) | Ignition switch ON, shift lever in neutral | 2.7 to 4.3 V |
A67-8 (TMN) - A67-25 (TME2) | Ignition switch ON, shift lever in any position other than neutral | 0.7 to 1.9 V |
OK |
| REPLACE ENGINE STOP AND START ECU |
NG |
| REPLACE NEUTRAL POSITION SWITCH |
DESCRIPTION HINT: This DTC is applicable to Manual Transaxle models only. The clutch stroke sensor assembly (for detecting pedal depression amount) and clutch switch assembly (for detecting the pedal depression endpoint) are installed to the clutch pedal...
DESCRIPTION When the number of starter operations reaches the maximum number, the engine stop and start ECU stores DTC P154563 and blinks the stop and start cancel indicator...
Other information:
DESCRIPTION Problem Symptom Suspected Area Trouble Area
Engine does not crank
Engine cranks slowly
Auxiliary battery depletion
Starter malfunction
Starter system
Auxiliary battery depletion
Starter malfunction
Starter circuit
Excessive engine friction Engine Engine assembly
Starting time is long
Engine speed fluctuation due to abnormal combustion
Idle speed too low or high
The engine stalls immediately after starting
Strong engine vibration due to above symptoms
Ignition malfunction
Deviation in air fuel ratio (Excessive or insufficient intake air volume or fuel supply)
Insufficient compression
Changes in load from another system
Ignition system
Spark plug
Ignition coil assembly
Fuel system
Direct fuel injector assembly
Port fuel injector assembly
Fuel pump assembly (for high pressure side)
Fuel pump (for low pressure side)
Fuel pump control circuit
Fuel suction plate sub-assembly
Fuel main valve assembly
Fuel line
Purge VSV system
Fuel quality (existence of foreign matter, degradation)
Intake and exhaust systems
Mass air flow meter sub-assembly
Intake system
(Air leaks or deposit accumulation)
Throttle body with motor assembly
Air fuel ratio sensor (sensor 1)
Air fuel ratio sensor (sensor 2)
Cam timing oil control solenoid assembly
Variable Valve Timing system (VVT system)
Other control systems
ECM
Wire harness or connector
Knock control sensor
Engine coolant temperature sensor
Immobiliser system
Engine
Water control valve
Engine assembly
Crankshaft position sensor
High load from another system
Air conditioning system
Power steering system
Electrical load signal system
SYMPTOM AND CAUSE OF SYSTEM MALFUNCTION HINT: The following are descriptions of the characteristics of each system malfunction...
REMOVAL CAUTION / NOTICE / HINT The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed, installed or replaced during the No. 1 side airbag sensor removal/installation are shown below...
Categories
The fuel gauge shows approximately how much fuel is remaining in
the tank when the ignition is switched ON. We recommend keeping
the tank over 1/4 full.

Full
1/4 Full
Empty
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