Workshop Manual

6E–233
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
DTC P0174 – Fuel Trim System Lean Bank 2 (Cont'd)
Step NoYesValue(s)Action
10 1. Visually and physically inspect the throttle body,
intake manifold, EGR valve and the EGR feed pipe
for vacuum leaks.
2. Repair any vacuum leaks as necessary.
Did your inspection reveal a vacuum leak?
— Verify repair Go to Step 11
11 Check the fuel for excessive water, alcohol, or other
contaminants (see Diagnosis in Engine Fuel for
procedure) and correct the contaminated fuel condition
is present (see Engine Fuel ).
Was the fuel contaminated?
— Verify repair Go to Step 12
12 1. Visually and physically inspect the PCM injector
grounds, power grounds and sensor grounds to
ensure that they are clean, tight, and in their proper
locations.
2. If a faulty ground condition is present, correct it as
necessary.
Did your inspection reveal a condition requiring repair?
— Verify repair Go to Step 13
13 1. Disconnect the MAF sensor electrical connector.
2. Operate the vehicle in “closed loop” while
monitoring the “BANK 2 S.T. FUEL TRIM” displayed
on the Tech 2.
Does the “BANK 2 S.T. FUEL TRIM” value decrease to
near the specified value?
0% Go to Step 19 Go to Step 14
14 Perform the procedure in the ”Fuel System Pressure
Test” and repair fuel system problem if necessary.
Did the Fuel System Pressure Test isolate a condition
requiring repair?
— Verify repair Go to Step 15
15 1. Visually and physically inspect the intake manifold,
injector O-rings, EGR adapter, EGR valve and the
EGR feed pipes for vacuum leaks.
2. Repair any problem that is found.
Did your inspection reveal a problem?
— Verify repair Go to Step 16
16 Visually and physically inspect the Bank 2 exhaust
manifold for leaks and loose or missing hardware and
correct any problem found.
Did your inspection reveal a problem?
— Verify repair Go to Step 17
17 Perform the “Injector Balance Test” and correct any
problem found (refer to Fuel Metering System ).
Did the Injector Balance Test isolate a problem?
— Verify repair Go to Step 18
18 1. Visually and physically inspect the Bank 2 HO2S 1
to ensure that it is installed securely and that the
Bank 2 HO2S 1 pigtail and wiring harness are not
contacting the exhaust or otherwise damaged.
2. If a problem is found, correct it as necessary.
Did your inspection reveal a problem?
— Verify repair
Refer to
Diagnostic
Aids
19 Replace the MAF sensor.
Is the action complete?
— Verify repair —