Code No. U1102: ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <Vehicle with ASC> Time-out

caution

If Diagnosis Code U1102 is output from engine-ECU or engine-A-M/T-ECU surely perform CAN busline diagnosis.

caution

Replace ECU after certainly confirming that the communication circuits are normal.

TROUBLE JUDGMENT

Check Conditions

While the cranking switch is in "OFF" position, or when 3 seconds pass after the cranking switch is in "OFF" from "ON".
The battery voltage is 10 V or more.

Judgment Criterion

The signals cannot be received from ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC> through CAN busline.

COMMENT ON TROUBLE SYMPTOM

Current malfunction

The failure is possibly caused by malfunction of the harness and connector in CAN busline between engine-ECU or engine-A-M/T-ECU and ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC> or between engine-ECU or engine-A-M/T-ECU and ABS-ECU <Vehicle without ASC> and ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC>, by malfunction in the power supply system of ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC>, in ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC> itself, in engine-ECU or engine-A-M/T-ECU.

Past malfunction

Focus on diagnosing malfunction of the harness and connector in CAN busline between engine-ECU or engine-A-M/T-ECU and ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC> as well as malfunction in the power supply system of ABS-ECU. Refer to past trouble (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Treat Past Trouble

) for the diagnosis procedure.

note

In case of Past trouble, M.U.T.-III CAN bus diagnosis cannot detect the failure even if there is malfunction in CAN bus, so that check CAN busline in the same way as Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

). The diagnosis codes being output to each ECU with CAN communication can narrow down the most suspected area (Refer to GROUP 54C - Troubleshooting - Can Bus Diagnosis Table

PROBABLE CAUSES

Failed of the harness and the connector
Failed engine-ECU or engine-A-M/T-ECU
Failed ABS-ECU <Vehicle without ASC>
Failed ABS/ASC-ECU <vehicle with ASC>

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis

warning

Since the radiator fan rotates during CAN bus line diagnostics, make sure that no one is servicing the engine compartment before diagnosing the CAN bus line. Since the CAN communication stops when diagnosing the CAN bus line, the ETACS-ECU detects the time-out of the engine-ECU or engine-A-M/T-ECU, and activates the radiator fan to prevent overheating as fail-safe.

Using M.U.T.-III, perform CAN busline diagnosis.

Q. Is the check result normal?

	Go to Step 2 .

	Correct CAN busline (Refer to GROUP 54C - Diagnosis - CAN Bus Diagnosis Table ), and then go to Step 6 .

STEP 2. M.U.T.-III other system diagnosis code

Confirm whether the diagnosis codes are output from ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC>.

Q. Is the diagnosis code output?

	Perform the troubleshooting of ABS (Refer to GROUP 35B - Troubleshooting - Check Chart for Diagnosis Codes ).

	Go to Step 3 .

STEP 3. M.U.T.-III other system diagnosis code

Confirm whether Diagnosis Code U1102: ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC> time-out is output from the following ECU having CAN communication with ABS-ECU.

Combination meter

Q. Is the diagnosis code output?

	Go to Step 4 .

	Go to Step 5 .

STEP 4. Reconfirmation of diagnosis codes

Reconfirm whether the diagnosis codes are output from engine-ECU or engine-A-M/T-ECU.

Erase the diagnosis codes being output.
Ignition switch: "LOCK" (OFF) to ON
Confirm whether the diagnosis codes are output.

Q. Q: Is the diagnosis code output?

	After replacing ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC>, go to Step 6 .

	Temporary malfunction in CAN busline between engine-ECU or engine-A-M/T-ECU and ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC> (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 5. Reconfirmation of diagnosis codes

Reconfirm whether the diagnosis codes are output from engine-ECU or engine-A-M/T-ECU

Erase the diagnosis codes being output.
Ignition switch: "LOCK" (OFF) to ON
Confirm whether the diagnosis codes are output.

Q. Q: Is the diagnosis code output?

	After replacing engine-ECU or engine-A-M/T-ECU, go to Step 6 .

	Temporary malfunction in CAN busline between engine-ECU or engine-A-M/T-ECU and ABS-ECU <Vehicle without ASC> or ABS/ASC-ECU <vehicle with ASC> (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 6. Reconfirmation of diagnosis codes

Reconfirm whether the diagnosis codes are output from engine-ECU or engine-A-M/T-ECU

Erase the diagnosis codes being output.
Ignition switch: "LOCK" (OFF) to ON
Confirm whether the diagnosis codes are output.

Q. Is the diagnosis code output?

	Go to Step 1 .

	The check is completed.