Description
This is the power source for the tire pressure warning ecu.
Wiring diagram

Inspection procedure
Notice:
It is necessary to register an id code after replacing the tire pressure monitor valve and/or the tire pressure warning ecu (see page tw-9).
Standard resistance:
below 1 


Standard resistance

Standard voltage 
Standard resistance 
Proceed to next circuit inspection shown in problem symptoms table
Tire pressure warning light circuit
Tire pressure warning receiver (w/ antenna)Gcwr, twr and unbraked twr
Confirm that the gross trailer weight, gross combination weight, gross
vehicle weight, gross axle weight and tongue weight are all within the
limits.
Gcwr*
2Wd models: 5985 lb. (2715 Kg)
Awd models: 6100 lb. (2765 Kg)
Twr*
1500 Lb. (680 Kg)
Unbraked twr*
1000 Lb. (450 Kg)
*: ...
Inspection
Inspect cylinder head for warpage
Using a precision straightedge and feeler gauge,
measure the warpage of the contact surfaces of the
cylinder block and manifolds.
Maximum warpage:
0.08 Mm (0.0032 In.)
If the warpage is greater than the maximum, replace
the cylinder head sub-a ...
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove front seat track bracket outer
cover lh (see page se-11)
Remove fr ...