MACS Service Reports - 2016 - MAY6

techauthority.com
Figure 9: Diagram of Jeep/Viper hydraulic fan system powered off power steering system. Labels are: 1) pump reservoir; 2) pump; 3) hydraulic fan assembly;
4) fan; 5) fan hydraulic motor; 6) hydraulic cooler; 7) steering gear.

May 2016

80 psi (any higher indicates a restriction). At 1500 engine
rpm, the flow should be 2.4-2.8 gallons/minute at 200 psi
if the fan motor is good. Anything lower indicates a defective fan.
At this stage, the problem areas you're likely to see are
with a bad sensor, a hydraulic leak, weak pump or maybe even an internal leak in the steering gear unit, which
should be reflected in the way the steering feels. ■

techauthority.com

is controlled by the PCM, supplying a pulse-width modulated signal to the control solenoid in a 0-100% range.
The PCM decision is from monitoring two inputs: coolant
temperature and A/C high side pressure. (Figures 9, 10).
The hydraulic fan and drive (fan blade, drive and
shroud) are a matched assembly and Chrysler never sold
detail parts for it - you have to get the whole assembly.
There are two hydraulic connections and one electrical (for
the solenoid).
Without a DRB III (which for the hydraulic fan system
just functions as a duty-cycle command tool), about all you
can do is listen for a fan speed increase as engine rpm goes
up. This is not necessarily easy and certainly not precise,
but the only spec anywhere is at least 1100 rpm (as measured with a photo tach) at 2200 rpm - ON LEXUS, NOT
JEEP (with a jumper across the E1 ground and the OP1 terminals of the Lexus underhood diagnostic plug).
You may get some trouble code on Jeep and Viper, particularly: P1499 for a shorted or open hydraulic flow solenoid, perhaps P1598 or P1599 for a bad A/C pressure
transducer or P1198 or P1199 for a coolant temperature
sensor failure. But more likely you'll have to look at the
actual measured temperature by the coolant sensor and/
or A/C pressure sensor.
In addition, if you know someone who has them, you
can put together the adapters and flow tester (it was part
of a Chrysler power steering analyzer). A pump pressure
gauge should read 70-100 psi when the engine is idling,
and at 1100 engine rpm the flowmeter should read at
least 2.6 gallons/minute or higher if the pump is healthy.
There's also a flow test from the fan motor to the steering
gear that can be done next. Initial pressure should be 50-

Figure 10: Back view of Jeep/Viper hydraulic fan motor. Labels are: 1)
low-pressure line; 2) and 3) high-pressure lines; 4) solenoid connector.

6

MACS Service Reports



http://www.techauthority.com http://www.techauthority.com

Table of Contents for the Digital Edition of MACS Service Reports - 2016

MACS Service Reports - 2016 - JAN1
MACS Service Reports - 2016 - JAN2
MACS Service Reports - 2016 - JAN3
MACS Service Reports - 2016 - JAN4
MACS Service Reports - 2016 - JAN5
MACS Service Reports - 2016 - JAN6
MACS Service Reports - 2016 - JAN7
MACS Service Reports - 2016 - JAN8
MACS Service Reports - 2016 - FEB1
MACS Service Reports - 2016 - FEB2
MACS Service Reports - 2016 - FEB3
MACS Service Reports - 2016 - FEB4
MACS Service Reports - 2016 - FEB5
MACS Service Reports - 2016 - FEB6
MACS Service Reports - 2016 - FEB7
MACS Service Reports - 2016 - FEB8
MACS Service Reports - 2016 - MAR1
MACS Service Reports - 2016 - MAR2
MACS Service Reports - 2016 - MAR3
MACS Service Reports - 2016 - MAR4
MACS Service Reports - 2016 - MAR5
MACS Service Reports - 2016 - MAR6
MACS Service Reports - 2016 - MAR7
MACS Service Reports - 2016 - MAR8
MACS Service Reports - 2016 - APR1
MACS Service Reports - 2016 - APR2
MACS Service Reports - 2016 - APR3
MACS Service Reports - 2016 - APR4
MACS Service Reports - 2016 - APR5
MACS Service Reports - 2016 - APR6
MACS Service Reports - 2016 - APR7
MACS Service Reports - 2016 - APR8
MACS Service Reports - 2016 - MAY1
MACS Service Reports - 2016 - MAY2
MACS Service Reports - 2016 - MAY3
MACS Service Reports - 2016 - MAY4
MACS Service Reports - 2016 - MAY5
MACS Service Reports - 2016 - MAY6
MACS Service Reports - 2016 - MAY7
MACS Service Reports - 2016 - MAY8
MACS Service Reports - 2016 - JUN1
MACS Service Reports - 2016 - JUN2
MACS Service Reports - 2016 - JUN3
MACS Service Reports - 2016 - JUN4
MACS Service Reports - 2016 - JUN5
MACS Service Reports - 2016 - JUN6
MACS Service Reports - 2016 - JUN7
MACS Service Reports - 2016 - JUN8
MACS Service Reports - 2016 - JUL1
MACS Service Reports - 2016 - JUL2
MACS Service Reports - 2016 - JUL3
MACS Service Reports - 2016 - JUL4
MACS Service Reports - 2016 - JUL5
MACS Service Reports - 2016 - JUL6
MACS Service Reports - 2016 - JUL7
MACS Service Reports - 2016 - JUL8
MACS Service Reports - 2016 - AUG1
MACS Service Reports - 2016 - AUG2
MACS Service Reports - 2016 - AUG3
MACS Service Reports - 2016 - AUG4
MACS Service Reports - 2016 - AUG5
MACS Service Reports - 2016 - AUG6
MACS Service Reports - 2016 - AUG7
MACS Service Reports - 2016 - AUG8
MACS Service Reports - 2016 - SEP1
MACS Service Reports - 2016 - SEP2
MACS Service Reports - 2016 - SEP3
MACS Service Reports - 2016 - SEP4
MACS Service Reports - 2016 - SEP5
MACS Service Reports - 2016 - SEP6
MACS Service Reports - 2016 - SEP7
MACS Service Reports - 2016 - SEP8
MACS Service Reports - 2016 - OCT1
MACS Service Reports - 2016 - OCT2
MACS Service Reports - 2016 - OCT3
MACS Service Reports - 2016 - OCT4
MACS Service Reports - 2016 - OCT5
MACS Service Reports - 2016 - OCT6
MACS Service Reports - 2016 - OCT7
MACS Service Reports - 2016 - OCT8
MACS Service Reports - 2016 - NOV1
MACS Service Reports - 2016 - NOV2
MACS Service Reports - 2016 - NOV3
MACS Service Reports - 2016 - NOV4
MACS Service Reports - 2016 - NOV5
MACS Service Reports - 2016 - NOV6
MACS Service Reports - 2016 - NOV7
MACS Service Reports - 2016 - NOV8
MACS Service Reports - 2016 - DEC1
MACS Service Reports - 2016 - DEC2
MACS Service Reports - 2016 - DEC3
MACS Service Reports - 2016 - DEC4
MACS Service Reports - 2016 - DEC5
MACS Service Reports - 2016 - DEC6
MACS Service Reports - 2016 - DEC7
MACS Service Reports - 2016 - DEC8
https://www.nxtbook.com/nxtbooks/macs/servicereports_2022
https://www.nxtbook.com/nxtbooks/macs/servicereports_2021
https://www.nxtbook.com/nxtbooks/macs/servicereports_2020
https://www.nxtbook.com/nxtbooks/macs/servicereports_2019
https://www.nxtbook.com/nxtbooks/macs/servicereports_2018
https://www.nxtbook.com/nxtbooks/macs/servicereports_2017
https://www.nxtbook.com/nxtbooks/macs/servicereports_2016
https://www.nxtbook.com/nxtbooks/macs/servicereports_2015
https://www.nxtbookmedia.com