Chery Tiggo 5 (T21). Manual - part 381

34–

DTC Confirmation Procedure

Confirm that battery voltage is between 11 and 14 V before performing the following procedures.
 Turn ignition switch to LOCK.
 Connect X-431 3G diagnostic tester (the latest software) to Data Link Connector (DLC), and make it

communicate with vehicle electronic module by the data network.

 Turn ignition switch to ON.
 Using X-431 3G diagnostic tester to record and clear the DTCs stored in the TCU.
 Turn ignition switch to LOCK and wait for a few seconds.
 Turn ignition switch to ON, and then select "Read Code".
 If DTC is detected, the malfunction indicated by the DTC is current. Go to the diagnosis procedure - Step 1.
 If DTC is not detected, the malfunction indicated by the DTC is intermittent. Please refer to Intermittent

DTC Troubleshooting.

Diagnosis Procedure

a. Turn ignition switch to LOCK.
b. Loosen and retighten the ground bolt or nut.
c. Check the installation position of the ground connection.

a. Turn ignition switch to LOCK.

DTC

U0100

Lost communication With ECM authentication frame

DTC

U0073

Control Module communication Bus Off

DTC Code

DTC Definition

DTC Detection

Conditions

Possible Causes

U0100

Lost communication
With ECM
authentication frame

Ignition switch ON

 Wire harness or connector
 ECM

U0073

Control Module
communication Bus
Off

Ignition switch ON

 CAN Line

CAUTION

 If the ECM or immobilizer control module is replaced, match the system with the X-431 3G diagnostic

tester (

See page 34-7

Check the ground connection

Repair or replace ground connection

Check engine control module (ECM) connector

34–

b. Disconnect the ECM connector E-033.

c. Check if the connector is damaged.

a. Turn ignition switch to LOCK.
b. Disconnect the immobilizer control module connector



I-018 and immobilizer coil connector.

c. Check if the connectors are damaged.

RT21380241

Repair or replace connector if necessary

Check immobilizer control module connector and immobilizer coil connector

RT21340100

Repair or replace connectors if necessary

Replace ECM

Repair or replace CAN BUS line

System is operating normally

34–

ON-VEHICLE SERVICE

Immobilizer Control Module

Removal & Installation

1. Turn off all the electrical devices and ignition switch.
2. Disconnect the negative battery cable.
3. Remove the right lower instrument panel protector (

See page 45-17

4. Disconnect the connectors (arrow) and remove the fixing

bolt (1) of the immobilizer control module with a wrench.



(Tightening torque: 7 ± 1 N·m)

Installation is in the reverse order of removal.

RT21340101

CAUTION

 Install the connectors in place.
 Tighten the fixing bolt in place.

LIGHTING SYSTEM

GENERAL INFORMATION

35-3