AUTOMATIC GEARBOX - ZF4HP22 - 24: DESCRIPTION AND OPERATION (page 4 of 4)

AUTOMATIC GEARBOX - ZF4HP22 - 24

44-20

DESCRIPTION AND OPERATION

P1613

(1)

* Solenoid valves 
power supply relay, 
sticking open or short 
circuit

Limp home mode in low and high ranges. Shift 
pressure to maximum, harsh gear shifts/
engagement.

On

On

P1705

(39)

Transmission high/low 
range, implausible 
input

No apparent effect

On

Off

P1810

(12, 13)

Sport/Manual warning 
lamp circuit fault

Lamp fails bulb check or is permanently 
illuminated. No effect on gearbox operation.

On

Off

P1841

(16)

* CAN bus fault

Maintains current gear in low range, limp 
home mode in high range. Shift pressure to 
maximum, harsh gear shifts/engagement.

On

On

P1842

(15)

* CAN level monitoring

Maintains current gear in low range, limp 
home mode in range. Shift pressure to 
maximum, harsh gear shifts/engagement.

On

On

P1843

(17)

* CAN time-out 
monitoring

Maintains current gear in low range, limp 
home mode in high range. Shift pressure to 
maximum, harsh gear shifts/engagement.

On

On

P1884
(11)

* CAN message: 
Engine friction invalid

No apparent effect.

On

Off

P1884
(18)

* CAN message: 
Throttle position invalid

Substitute throttle angle of 50% adopted. No 
kickdown. Operates in economy modes only.

On

On

P1884
(19)

CAN message: Engine 
temperature invalid

Substitute engine temperature derived from 
other inputs. No apparent effect.

On

Off

P1884
(20)

CAN message: Road 
speed invalid

No apparent effect

On 

Off

P1884
(33, 34)

* CAN message: 
Engine torque invalid

Substitute engine torque of derived from other 
inputs. May affect shift quality.

On

Off

P1884
(35)

* CAN message: 
Engine speed invalid

Maintains current gear in low range, limp 
home mode in high range. Shift pressure to 
maximum, harsh gear shifts/engagement.

On

On

P1884
(37)

CAN message: Engine 
air intake temperature 
invalid

No apparent effect.

On

Off

P1844

(38)

Altitude shift control 
invalid

No reduced torque compensation, possible 
reduction in performance/ driveability at 
altitude or high ambient temperatures.

On

Off

* = Emissions (OBD II) relevant
†On = MIL illuminates immediately (in all other faults, MIL On = illuminates in the 2nd consecutive drive cycle if 
fault still present)

Fault code, 

OBD II 

(TestBook)

Fault description

Effect

Warning lamp 

illumination

MIL

Sport/ 

Manual