Ford Electric Ranger 2001 Manual page 185

211-02-7
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST A: DTC C1778 POWER STEERING FAILURE
• Measure the resistance between circuit 3140 (BK wire) terminal and
circuit 3141 (W wire) terminal on power steering assembly C1895M.
• Is the resistance less than 10 ohms?
A16 CHECK HVPDB FOR SHORT
• Measure the resistance between circuit 3140 (BK wire) and circuit 3141
(W wire) on power steering assembly C1895F.
• Is the resistance greater than 10,000 ohms?
A17 CHECK SYSTEM
• With key OFF, reconnect all component connectors that were
disconnected.
• Reconnect the 12-volt auxiliary battery negative cable.
• With key ON, turn the steering wheel from lock-to-lock.
• Does the 10A PWR STR high-voltage fuse fail again?
PINPOINT TEST B: MORE THAN USUAL STEERING EFFORT REQUIRED TO TURN STEERING WHEEL
(POWER STEERING PUMP SPEED DOES NOT INCREASE WHILE TURNING THE STEERING WHEEL)
B1 CHECK POWER STEERING PUMP OPERATION
NOTE: Carry out the following steps with the hood raised. The speed of
the power steering pump should increase when the steering wheel is turned
and return to a slower speed after the steering wheel is released.
• With key ON, turn the steering wheel 90 degrees while listening to the
speed of the power steering pump.
• Does the power steering pump speed increase?
B2 CHECK STEERING WHEEL SENSOR SIGNALS
• With key OFF, disconnect power steering assembly C1992.
• With key ON, measure the voltage between pin 6 (BR wire), pin 7 (R
wire) on power steering assembly C1992 and ground while turning the
steering wheel from left to right and right to left.
• Do the voltages fluctuate between 0 and 5 volts?
B3 CHECK POWER TO STEERING WHEEL SENSOR
• With key OFF, disconnect steering wheel sensor C2990.
• With key ON, measure the voltage between pin 4 (LB/PK wire) on
steering wheel sensor C2990 and ground.
• Is the voltage greater than 10 volts?
B4 CHECK CIRCUITS 3226 (BK/LG), 3227 (R), AND 3228 (BR) FOR
OPEN(S)
• With key OFF, measure the resistance of the BK/LG wire between pin 1
on steering wheel sensor C2990 and pin 5 on power steering assembly
C1992.
(Continued)
Power Steering
TEST STEP
TEST STEP
ACTION TO TAKE
Yes = REPLACE the power
steering assembly.
No = GO to A16.
GO to A17.
Yes =
No = REPLACE the HVPDB.
REFER to Section 414-03A
or Section 414-03B.
Yes = REPLACE the power
steering assembly.
No = System OK.
ACTION TO TAKE
Yes = CHECK the power steering
fluid level and tire pressures.
If necessary, FILL to the
appropriate level. If OK,
CHECK the steering
alignment and steering gear.
REPAIR as necessary.
GO to B2.
No =
Yes = REPLACE the power
steering assembly.
No = GO to B3.
GO to B4.
Yes =
No = REPAIR the LB/PK wire.
GO to B5.
Yes =
2001 Ranger EV, 01/2001
211-02-7