Page 134 - Foton Workshop Manual - Auman EST-M

DI - 80 Diagnosis - Diagnosis-fault diagnosis of electronic and electrical parts

The starter rotates, but the engine can’t start.
Fault diagnosis chart

Failure phenomenon Possible reason Failure elimination
1. Fuel quality poor ● Replace fuel

2. Pre-heating circuit (no sufficient ● Check if the pre-heater circuit is ok
pre-heating) ● Check if the preheater resistance is ok

● Check the crankshaft/camshaft
3. Its operation time sequence can’t be
position sensor is ok
built.
● Check if the connector and wire are ok
● Check if the high pressure oil pump
supplies sufficient oil rail pressure
4. High-pressure fuel pump (insufficient ● Check if the oil metering cell is
fuel supply capacity of high-pressure broken
pump) ● Check the low-pressure fuel line for
The starter can drive the rotation of
blockage, fuel injector for seizure,
engine at normal speed, obvious driving
high-pressure oil pipe for breakage, etc.
possibility, but it can’t be started.
● Check an replace the fuel pressure
5. Fault of fuel pressure sensor
sensor.

● Check if the injector drive circuit
(including the connector) is open/short
● Check if the high pressure oil pipe
leaks
6. Fuel injector (failure of fuel injection)
● Check if the injector is broken or there
is carbon deposit
● Check the crankshaft position sensor
● Check the camshaft position sensor

7. ECM failure ● Replace ECM
Diagnosis procedure
1. Check the fuel

a. Check if there is water or impurities in the fuel.
Check if the result is ok?
Yes>go to Step 2.
NO>replace the fuel and clean the fuel tank.

2. Check the pre-heater fuse and relay
a. Ignition switch: LOCK.

b. Disconnect the cable of battery negative pole.
c. Pull out the preheating fuse, and observe whether the fuse is molten.

d. Pull out the preheating relay, and adopt a multimeter to measure the conductivity between pins 85 and 86 or
pins 30 and 87.

DI-080