(a)  Connect the fault diagnosis tester to the diagnostic interface. 

(b)  Turn ignition switch to ON position. 

(c)  Clear DTC code. 

(d)  Start and run the engine at idle speed to warm up the engine for at least 5 min. 

(e)  Read control system DTC code again to confirm that the system has no DTC code exported. 

 

Step 13 

Troubleshooting 

5. Maintenance 

guide 

: 

Refer to2.10.7.1 Replacement of Camshaft Position Sensor to replace the intake CMP sensor. 

No 

Refer to 2.2.7.3 Intermittent Fault 
Inspection for intermittent fault. 

Yes 

843

2.12.7.37 DTC P0351 P0352 P0353 P0354 

1. DTC 

description: 

DTC  P0351 

Cylinder 1 Ignition Circuit malfunction 

 

DTC  P0352 

Cylinder 2 Ignition Circuit malfunction 

 

DTC  P0353 

Cylinder 3 Ignition Circuit malfunction 

 

DTC  P0354 

Cylinder 4 Ignition Circuit malfunction 

Ignition coil #1 initiate the ignition for Cylinder #1; ignition coil #2 initiate the ignition for 
Cylinder #2; ignition coil #3 initiate the ignition for Cylinder #3; ignition coil #4 initiate the 
ignition for Cylinder #4. The ignition relay supplies power for the four ignition coils. ECM uses 
the ECM harness connector EN01 terminal #4 to control Cylinder #1 ignition coil primary circuit 
to be grounded; uses the terminal #1 to control Cylinder #2 ignition coil primary circuit to be 
grounded; uses the terminal #62 to control Cylinder #3 ignition coil primary circuit to be grounded; 
uses the terminal #81 to control Cylinder #4 ignition coil primary circuit to be grounded. 

2.  DTC Code Set Up and Removal Conditions: 

DTC Code 

DTC Detection 
Strategy 

Set(Control Strategy) Conditions Fault Locations 

P0351 

P0352 

P0353 

P0354 

Hardware 
Circuit 
Inspection 

Operating at idle, with the ignition 
coil control end disconnected, 
short to ground or short to power 
supply, this DTC code will be set. 
The fuel injection of the cylinder 
with this DTC code will stop 
leading to engine speed fluctuates.

1. Ignition 

Coil 

Circuit 

2. Ignition 

Coil 

3. ECM 

844

3. Circuit 

figure 

NL02-2098b

ECM

44

EN01

BAT

20A

E

F

22

MPR

86

87

30

85

发动机主继电器

4

EN01

1

EN01

A EN20

B EN20

C EN20

点火线圈

COILA

COILB

 

4. Diagnostic 

Steps: 

Refer to 2.10.6 “Diagnostic Information and Procedures” for ignition coil inspection. 

5. Maintenance 

guide 

Refer to 2.10.7.3 “Replacement of Ignition Coil” to replace the ignition coil. 

Engine 
main relay 

Ignition coil

845

2.12.7.38 DTC P0420 

1. DTC 

description: 

ECM uses two oxygen sensors (front oxygen sensor and rear oxygen sensor) installed before and 
after the three- way catalytic converters to monitor the conversion efficiency of the three-way 
catalytic converter (TWC). ECM uses front oxygen sensor for Air-fuel ratio close-loop control and 
monitors oxygen content in the exhaust gas not purified by TWC. The Post-catalytic oxygen 
sensor sends voltage signal to ECM indicating the oxygen content in the exhaust gas purified by 
the TWC. ECM compares signals from the two sensors to determine whether the TWC is currently 
under normal working condition. If the calculated TWC conversion efficiency is too low, the fault 
lamp will be lit and the DTC code will be set. 

2.  Conditions For Setting DTC and The Fault Location: 

DTC Code 

DTC Detection 
Strategy 

Conditions For Setting The DTC 
(Control Strategy) 

Fault Locations 

P0420 

Hardware 
Circuit 
Inspection 

Coolant temperature is higher than 
70°C (158 ?F), and the fuel system is 
in close-loop mode. After driving 
some distance and stop the vehicle, 
run the engine at idle, the system 
compares the front and rear oxygen 
sensor signals to calculate three-way 
catalyst converter oxygen storing 
time. When the oxygen storing time is 
less than the threshold, the system 
reports a fault. 

1. Front  Oxygen 

Sensor 

2. Rear  Oxygen 

Sensor 

3. Three-way 

Catalytic 
Converter. 

4. Exhaust 

Leak. 

3. Circuit 

sketch 

Refer to 2.12.6 Electrical Schematic Diagram. 

4. Diagnostic 

Steps: 

Note: Before carrying out this diagnosis step, observe the data list on fault diagnosis tester and 
analyze the accuracy of the data, as these will help with quick diagnosis. 

1 

Inspect whether there are control system DTC codes other than DTC 
P0420.

 

A.  Connect fault diagnosis tester to the vehicle diagnostic interface. 

B.  Rotated ignition switch to ON position. 

C.  Press the power button of fault diagnosis tester. 

D.  Select the following menu items: Engine/Read DTC codes. 

Read DTC code 

Results 

DTC Codes Shown 

To Step 

DTC  P0420 

Three-Way Catalytic Converter Conversion Efficiency Low 

846