Volvo Symptom D12D US02 Service Manual page 14

Group 20
Step 4: Component and Function Checks
Action:
Check supply voltage and ground signals at VECU on pins (PA12, PA13, PA14 and PB15)
according to checks in VECU Fault Code Manual.
Check the power supply/ground and wiring harness for engine ECU, including connectors
and terminal pins for damage or oxidation.
Check that fuel pump is pumping fuel at cranking speed.
Check the fuel pump for damage or abnormal wear, including axial play. Check the
condition of the seals.
Check for air in the fuel system.
Check that the fuel quality is within specifications and the tanks contain an adequate
amount.
Check that the EPG shutter functions properly and is not stuck in the active (closed)
position, either mechanically or by the AVU.
Check that the VCB control valve is regulating the proper oil pressure to the rocker arm
shaft when VCB is not active.
Note: If either valve or solenoid has failed allowing full system oil pressure
to the rocker arm shaft, this results with low cylinder compression. The
VCB rocker arms are opening the exhaust valves at inappropriate times,
which leads to black smoke and engine starting problems.
Check that the adjustable timing gear is correctly timed and torqued properly.
Check that the engine ECU receives correct signals from the camshaft and the flywheel
sensors during cranking.
"Engine Does Not Start" page 5
10
D
C2002641
Refer to:
Impact or ID DVD: "MID 144 Fault Codes",
Information type "Diagnostics", group 3649.
"Engine ECU, Fault Tracing"
Impact or ID DVD: Information type "Diagnostics",
group 2841.
"Fuel Supply Pressure, Fault Tracing"
(Checklist B), Impact or ID DVD: Information type
"Diagnostics", group 2309.
"Fuel Supply Pressure, Fault Tracing" (Checklist
B), Impact or ID DVD: Information type
"Diagnostics," Group 2309.
Group 23: Air in the Fuel System, Checking
Group 23: Fuel Quality, Checking
"Exhaust Pressure Governor, Fault
Tracing"
(Checklist E), Impact or ID DVD:
Information type "Diagnostics", group 2538.
"Rocker Arm Shaft Oil Pressure, Checking"
(Checklist O), Impact or ID DVD: Information type
"Diagnostics", group 2531.
Group 21: Camshaft Timing, Check. Impact or ID
DVD: Information type "Repair", Group 2154.
"Camshaft and Flywheel Signals, Fault Tracing"
(Checklist H), Impact or ID DVD: Information type
"Diagnostics" Group 2846.
(Checklist M),