Download P26B7

P26B7
Refer to Wiring Diagrams Cell 25 for schematic and connector information.
Normal operation and Fault Conditions The engine cooling system incorporates a coolant
bypass solenoid valve and a coolant shutoff solenoid valve. Using these two valves, the
coolant flow through the engine block can be restricted or completely stagnated. The
restriction or stagnation of the coolant flow makes it possible for the engine components to
warm up faster during the warm-up phase. Both solenoid valves are controlled by the PCM
via a low side driver. The PCM monitors both solenoids for electrical faults and sets an
appropriate DTC.
Possible Sources Fuse(s)
 Wiring, terminals or connectors
 Coolant bypass solenoid valve
 PCM
Diagnostic Trouble Code (DTC) Fault Trigger Conditions
DTC
Description
Fault Trigger Conditions
P26B7
Engine Coolant Bypass Valve The PCM monitors the Engine Coolant Bypass Valve
"C" Control Circuit/Open
"C" Control Circuit/Open circuit for high and low voltage.
The test fails if the voltage exceeds a calibrated limit for
a calibrated amount of time.
PINPOINT TEST D : PINPOINT TEST
WARNING: Always allow the engine to cool before opening the
cooling system. Do not unscrew the coolant pressure relief cap when the
engine is operating or the cooling system is hot. The cooling system is
under pressure; steam and hot liquid can come out forcefully when the
cap is loosened slightly. Failure to follow these instructions may result in
serious personal injury.
D1 CHECK THE COOLANT BYPASS SOLENOID VALVE CONNECTOR
FOR BEING FULLY SEATED

Check the coolant bypass solenoid valve C1676 for being fully seated.
Were any concerns found?
Yes REPAIR as needed.
No GO to D2
D2 CHECK THE COOLANT BYPASS SOLENOID VALVE RESISTANCE

Disconnect coolant bypass solenoid valve C1676.

measure:
Click to display connectors
Positive Lead
Measurement / Action
pin 1 (component side)
Negative Lead
pin 2 (component side)

Is the resistance between 9-12 ohms?
Yes GO to D3
No INSTALL a new coolant bypass solenoid valve.
REFER to: Coolant Bypass Solenoid Valve (303-03B Engine
Cooling - 1.6L EcoBoost (132kW/180PS) - Sigma, Removal and
Installation).
D3 CHECK FOR VOLTAGE TO THE COOLANT BYPASS SOLENOID
VALVE

Ignition ON.

Measure:
Click to display connectors
Positive Lead
Measurement / Action
C1676-2
Negative Lead
Ground

Is voltage greater than 11 volts?
Yes GO to D4
No VERIFY the BJB fuse 12 (15A) is OK. If the fuse is OK, REPAIR
the circuit. If not OK, REFER to the Wiring Diagrams manual to
identify the possible causes of the circuit short.
D4 CHECK THE COOLANT BYPASS SOLENOID VALVE CIRCUIT FOR A
SHORT TO POWER

Ignition OFF.

Disconnect PCM C1232E.

Ignition ON.

Measure:
Click to display connectors
Positive Lead
Measurement / Action
C1676-1
Negative Lead
Ground

Is any voltage present?
Yes REPAIR the circuit.
No GO to D5
D5 CHECK THE COOLANT BYPASS SOLENOID VALVE CIRCUIT FOR A
SHORT TO GROUND

Ignition OFF.

Measure:
Click to display connectors
Positive Lead
Measurement / Action
C1676-1
Negative Lead
Ground

Is the greater than 10,000 ohms?
Yes GO to D6
No REPAIR the circuit.
D6 CHECK THE COOLANT BYPASS SOLENOID VALVE CIRCUIT FOR AN
OPEN

Measure:
Click to display connectors
Positive
Lead
C1676-1

Measurement /
Action
Negative Lead
For auto transmission: C1232E-18 For
manual transmission: C1232E-2
Is the resistance less than 3 ohms?
Yes INSTALL a new coolant bypass solenoid valve.
REFER to: Coolant Bypass Solenoid Valve (303-03B Engine
Cooling - 1.6L EcoBoost (132kW/180PS) - Sigma, Removal and
Installation).
CLEAR the DTC. TEST the system for normal operation. If the
DTC is still present GO to D7
No REPAIR the circuit.
D7 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE)
OPERATION

Ignition OFF.

Disconnect and inspect all the PCM connectors.

Repair:

corrosion (install new connector or terminals - clean module
pins)


damaged or bent pins - install new terminals/pins
pushed-out pins - install new pins as necessary

Reconnect the PCM connectors. Make sure they seat and latch
correctly.

Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable Technical Service Bulletins
(TSBs). If a TSB exists for this concern, discontinue this test and
follow TSB instructions. If no Technical Service Bulletins (TSBs)
address this concern, INSTALL a new PCM.
REFER to: Powertrain Control Module (PCM) (303-14B
Electronic Engine Controls - 1.6L EcoBoost (132kW/180PS) Sigma, Removal and Installation).
No The system is operating correctly at this time. The concern may
have been caused by module connections. Address the root
cause of any connector or pin issues.