Changan CS35 User Manual

3.1.13-158
CS35 2013.04
3.1.13-158Electronic Control System - ME7
DTC P0170, P0171, P0172, P2177, P2178, P2187, P2188
1. DTC Description
2. Possible Sources
Fault Code Description Definition
P0170
Offline inspecting air - fuel ratio
closed loop control self-learning
unreasonable
Engine control module (ECM) controls closed loop
air - fuel ratio measuring system, it controls the per-
formance, fuel economy and emissions control to
achieve the best cooperation. In closed loop mode,
ECM monitors the voltage of the heating oxygen
sensor (HO2S) signal and regulate the fuel supply
according to the signal voltage.
Changes in fuel supply will change the fuel adjust-
ment value of long - term and short - term. The fuel
short - term adjust value will respond to the change
of heating oxygen sensor signal voltage and it will
change rapidly. These changes will be fine - tuning
the engine fuel supply. Long - term fuel regulating
value is in response to the short-term trends
change. Long - term fuel supply adjusts roughly, in
order to back to the center fuel value of short-term,
to recover the control to short - term adjust of the
fuel regulator.
Ideal value of the fuel adjustment is about 0 %. If the
fuel adjustment value is positive, it says the engine
control module is increasing fuel to compensate the
condition of fuel mixture is too lean. Negative value
of the fuel adjustment shows the engine control
module is reducing the fuel to compensate the thick
mixture.
P0171
Offline test air-fuel ratio close
loop control self - learning is too
thin
P0172
Offline test air - fuel ratio close
loop self - learning is too rich
P2177
Air - fuel ratio closed loop con-
trol self-learning value exceed
the upper limits (medium load
range)
P2178
Air - fuel ratio closed loop con-
trol self - learning value exceed
the lower limits (medium load
range)
P2187
Air - fuel ratio closed loop con-
trol self - learning value exceed
the upper limits (low load range)
P2188
Air - fuel ratio closed loop con-
trol self - learning value exceed
the lower limits (low load range)
Fault
Code
Test Tactics
Setting Conditions (Control
Strategy)
Fault
P0170
Hardware or circuit
inspection
-
• MAP sensor work fault
• Oxygen sensor fault
• Oxygen sensor circuit fault
• Oxygen sensor heater work
fault
• ECT sensor work fault
• Fuel system fault
• Ignition system performance
fault
• Engine mechanical problems
• Engine control accessory
fault
•ECM fault
P0171
P0172
P2177
P2178
P2187
P2188
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Changan CS35 Specifications

General

Brand	Changan
Model	CS35
Category	Automobile
Language	English