I got a code "9 hydraulic pump circuit malfunction" Any ideas on what to look at for this.
Its a 02 grand caravan. Thanks in advance.

 

PUMP CIRCUIT FAILURE

When Monitored: Ignition on. The CAB commands the pump on at 20 km/h (12 mph) to
check its operation, if the brake switch is not applied. If the brake is applied, the test will
run at 40 km/h (25 mph). The CAB monitors pump voltage every 7 milliseconds.
Set Condition: The DTC is stored when the CAB detects: 1) Improper voltage decay after
the pump was turned off. 2) Pump not energized by the CAB, but voltage is present for 3.5

seconds. 3) Pump is turned on by the CAB, but without sufficient voltage to operate it.


I've seen the harness rub through and get corroded down by the hydraulic unit bracket.

 

Check wiring loom, especially on all the connectors from Fuse Box to ABS unit. Most of the time is one of the connectors corroded off.
If nothing found visually, you HAVE to check for power and ground at the ABS pump before u condemn the ABS unit.
75% of the time this is a Wiring problem instead of the ABS unit failure. Mainly pay attention under the Fuse box.
The wiring loom runs under the Battery, and you have to remove the battery and battery tray to gain access to check the ABS unit. I recommend you to remove battery, put it aside, and use a remote jump cable to power vehicle for testing.

Of course, check for blown/missing fuse.

 

if nothing visual found, you HAVE to run the diagnostic tree for the code. The Pump cost $400 + 3 hrs of labors.

When Monitored and Set Condition:
PUMP CIRCUIT FAILURE

When Monitored: Ignition on. The CAB commands the pump on at 20 km/h (12 mph) to
check its operation, if the brake switch is not applied. If the brake is applied, the test will
run at 40 km/h (25 mph). The CAB monitors pump voltage every 7 milliseconds.
Set Condition: The DTC is stored when the CAB detects: 1) Improper voltage decay after
the pump was turned off. 2) Pump not energized by the CAB, but voltage is present for 3.5
seconds. 3) Pump is turned on by the CAB, but without sufficient voltage to operate it.

POSSIBLE CAUSES

PUMP HARNESS DISCONNECTED
CAB - PUMP MOTOR RUNNING CONTINUOUSLY
ABS PUMP MOTOR INTERMITTENT DTC
GROUND CIRCUIT HIGH RESISTANCE
FUSED B(+) CIRCUIT OPEN
GROUND CIRCUIT OPEN
CAB - INTERNAL FAULT
CAB - SETTING FALSE CODE

TEST ACTION APPLICABILITY

1 Turn the ignition off.
Turn the ignition on.
Monitor the pump motor for continuous operation.
Is the pump motor running continuously?
All
Yes

! Replace the Controller Anti-Lock Brake in accordance with the
Service Information. The vehicle must be driven at 25 km/h (15
mph) to extinguish the ABS indicator.
Perform ABS VERIFICATION TEST - VER 1.
No ! Go To 2
2 Turn the ignition on.
With the DRBIIIt, read DTC’s.
With the DRBIIIt, erase DTC’s.
Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, actuate the ABS pump motor.
Did the Pump Motor operate when actuated?
All
Yes ! Go To 3

No ! Go To 4


Yes

Continued

 

Thanks. Well, looks like I got some work to do.