Toyota Yaris: Stop And Start System / ECU Internal Error (P164400)
DESCRIPTION
If a malfunction is detected in the starter circuit, the engine stop and start ECU stores DTC P164400 and blinks the stop and start cancel indicator.
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory | Note |
P164400 | ECU Internal Error | Both of the following conditions are met for 0.2 seconds or more (1 trip detection logic): -
Ignition switch ON.
-
Malfunction in starter circuit (STA).
| -
Wire harness or connector
-
ST NO. 1 relay
-
Engine stop and start ECU
| Blinks | DTC stored | SAE Code: P1644 |
CONFIRMATION DRIVING PATTERN
HINT:
-
If the cable is disconnected from the auxiliary battery terminal, stop and start control is prohibited until refresh charge is completed.
In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item Status of Auxiliary Battery Charge Control changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the auxiliary battery fluid temperature at 11°C (52°F) or higher, the refresh charge will be completed.)
-
If the GTS is not available and the Data List item Status of Auxiliary Battery Charge Control cannot be checked, charge the auxiliary battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.
If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.
-
After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.
-
Allow the engine to idle for 3 minutes after it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.
CONFIRMATION AFTER TROUBLESHOOTING
(a) Clear the DTCs.
Powertrain > Stop and Start > Clear DTCs
(b) Start the engine and warm it up.
(c) Drive the vehicle at 7 km/h (4 mph) or more.
CAUTION:
When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.
(d) Stop the vehicle, move the shift lever to neutral and release the clutch pedal.
(e) Keep the engine stopped by stop and start control for 1 second or more.
(f) Depress the clutch pedal and start the engine.
(g) Check that DTCs are not output.
Powertrain > Stop and Start > Trouble Codes
STOP AND START SYSTEM OPERATION CHECK
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WIRING DIAGRAM
Refer to DTC P061519.
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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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-
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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If DTCs P060B1C (Analog to Digital Converter Circuit Voltage Out of Range), P060B49 (Analog to Digital Converter Internal Electronic Failure) or P060B71 (Analog to Digital Converter Actuator Stuck) and P164400 (ECU Internal Error) are output simultaneously,, perform troubleshooting for DTC P060B1C, P060B49 or P060B71 first as it may have caused DTC P164400 to be stored.
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-
If DTCs P061519 (Starter Relay Circuit Current Above Threshold) and P164400 (ECU Internal Error) are output simultaneously, perform troubleshooting for DTC P061519 first as it may have caused DTC P164400 to be stored.
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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. | CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P164400) |
(a) Read the DTCs.
Powertrain > Stop and Start > Trouble Codes
Result | Proceed to |
DTC P164400 is output | A |
DTCs P060B1C, P060B49 or P060B71 and P164400 are output | B |
DTCs P061519 and P164400 are output | C |
B |
| GO TO DTC P060B1C, P060B49 OR P060B71 |
C |
| GO TO DTC P061519 |
A |
| |
2. | CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - ST NO. 1 RELAY) |
(a) Disconnect the H45 certification ECU (smart key ECU assembly) connector.
(b) Disconnect the A64 clutch switch assembly connector.
(c) Disconnect the A67 engine stop and start ECU connector.
(d) Remove the ST NO. 1 relay from the No. 1 engine room relay block.
(e) Measure the resistance according to the value(s) in the table below.
Click here
Standard Resistance:
Tester Connection | Condition | Specified Condition |
A67-21 (STA) - 2 (ST NO. 1 relay holder) | Always | Below 1 Ω |
A67-21 (STA) - Body ground and other terminals | Always | 10 kΩ or higher |
2 (ST NO. 1 relay holder) - Body ground and other terminals | Always | 10 kΩ or higher |
NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
| |
3. | CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - CLUTCH SWITCH ASSEMBLY) |
(a) Disconnect the A67 engine stop and start ECU connector.
(b) Disconnect the A64 clutch switch assembly connector.
(c) Disconnect the H45 certification ECU (smart key ECU assembly) connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
A67-21 (STA) - A64-1 (L) | Always | Below 1 Ω |
NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
| |
4. | INSPECT RELAY (ST NO. 1 RELAY) |
(a) Inspect the ST NO. 1 relay.
Click here
NG |
| REPLACE RELAY (ST NO. 1 RELAY) |
OK |
| |
5. | CHECK HARNESS AND CONNECTOR (ST NO. 1 RELAY - BODY GROUND) |
(a) Remove the ST NO. 1 relay from the No. 1 engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
1 (ST NO. 1 relay holder) - Body ground | Always | Below 1 Ω |
OK |
| REPLACE ENGINE STOP AND START ECU |
NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
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Other information:
REMOVAL CAUTION / NOTICE / HINT NOTICE:
To avoid degrading the precision of the assembly, do not loosen or remove the 2 bolts shown in the illustration.
If the bolts have been loosened or removed, use the following procedure to reassemble the parts...
FAIL-SAFE CHART If any of the following DTCs are stored, the engine stop and start ECU enters fail-safe mode to preserve vehicle operability. DTC Component Fail-safe Operation Fail-safe Deactivation Condition P033562 Open in engine speed signal circuit
Stop and start control is prohibited
Engine is automatically restarted if a DTC is stored while the engine is stopped by stop and start control
All of the following conditions are met for 10 seconds:
Normal communication with ECM
Engine speed 500 rpm or higher
Engine speed (communication signal) 500 rpm or higher
Difference between engine speed from pulse signal and engine speed from communication signal is less than 100 rpm
P055500 P05552A
Vacuum sensor assembly
Brake booster assembly
Vacuum hose (brake booster hose)
Stop and start control is prohibited
Engine is automatically restarted if a DTC is stored while the engine is stopped by stop and start control
One of the following conditions is met:
Vacuum changes while the brake pedal is depressed
Vacuum changes a specified number of times while the vehicle is being driven faster than a certain vehicle speed
P055511 P055515 Vacuum sensor assembly circuit
Stop and start control is prohibited
Engine is automatically restarted if a DTC is stored while the engine is stopped by stop and start control
Sensor output is within standard range P060629 Engine stop and start ECU
Stop and start control is prohibited
Engine is automatically restarted if a DTC is stored while the engine is stopped by stop and start control
Pass condition detected and ignition switch turned to ON P060B1C P060B49 P060B71 Analog to digital converter (Engine stop and start ECU)
Stop and start control is prohibited
Engine is automatically restarted if a DTC is stored while the engine is stopped by stop and start control
Pass condition detected and ignition switch turned to ON P061519 ST NO...