Ford Electric Ranger 2001 Manual page 184

211-02-6
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST A: DTC C1778 POWER STEERING FAILURE
A10 CHECK CIRCUIT 3023 (BK/O) FOR OPEN
• With key OFF, disconnect power steering assembly C1992 and measure
the resistance of the BK/O wire between pin 17 on the power steering
assembly C1992 and BOB pin 99.
• Is the resistance less than 5 ohms?
A11 CHECK LOW VOLTAGE POWER TO POWER STEERING
ASSEMBLY
• With key ON, measure the voltage between pin 10 (LB/PK wire), pin 21
(LB/PK wire) on the power steering assembly C1992 and ground.
• Are the voltages greater than 10 volts?
A12 CHECK HIGH VOLTAGE POSITIVE BUS TO POWER
STEERING ASSEMBLY FOR OPEN
• Disconnect the 12-volt auxiliary battery negative cable.
WARNING: The following test steps contain high-voltage
procedures. High-voltage insulated safety gloves and face shield must
be worn when carrying out the following steps. Do not attempt to
check for high-voltage power at the power steering assembly
high-voltage connector. The close proximity of the connector pins may
cause an electrical arc. Failure to follow this warning may result in
severe personal injury or death.
• Disconnect power steering assembly high-voltage C1895.
• Disconnect high-voltage auxiliary load in-line C1935 on the traction
battery support tray.
• Measure the resistance between circuit 3140 (BK wire) on power steering
assembly C1895F and circuit 3132 (Y wire) on high-voltage auxiliary
load in-line C1935M.
• Is the resistance less than 5 ohms?
A13 CHECK HIGH-VOLTAGE FUSE
NOTE: If the 10A fuse is open, DO NOT replace the fuse until the cause
of the short is found and repaired. Replacing the fuse prior to repairing the
short will cause contactor failure.
• Disconnect all high-voltage power distribution box (HVPDB)
high-voltage connectors.
• Measure the resistance of the 10A PWR STR fuse.
• Is the resistance greater than 1,000 ohms?
A14 CHECK POWER STEERING ASSEMBLY FOR CAPACITOR
DISCHARGE FAILURE
WARNING: Carefully probe the terminals of the power steering
assembly. The power steering assembly contains high-voltage
capacitors that can retain high voltage if there is a capacitor discharge
failure. Shorting the probes together may cause an electrical arc.
• Measure the voltage between circuit 3140 (BK wire) terminal and circuit
3141 (W wire) terminal on power steering assembly C1895M.
• Is the voltage greater than 0 volts?
A15 CHECK POWER STEERING ASSEMBLY FOR SHORT
(Continued)
Power Steering
TEST STEP ACTION TO TAKE
GO to A11.
Yes =
No = REPAIR the BK/O wire.
Yes = GO to A12.
No = REPAIR the LB/PK wire(s)
in question.
Yes = REPLACE the power
steering assembly.
No = GO to A13.
Yes = REPLACE the 10A PWR
STR fuse. GO to A14.
No = REPLACE the HVPDB.
REFER to Section 414-03A
or Section 414-03B.
Yes = REPLACE the power
steering assembly.
GO to A15.
No =
2001 Ranger EV, 01/2001
211-02-6