See Figures 1, 2, 3, 4, 5, 6 and 7
The control module performs system tests and self-tests during start up and normal operation. The valve, sensor, and fluid level circuits are monitored for proper operation. If a fault is found, the anti-lock system will be deactivated and the warning light will be illuminated. Most faults will cause the warning light to stay on until the ignition is turned off. While the light is illuminated a diagnostic flashout code may be obtained. However, there are certain faults (those associated with the fluid level switch or loss of power to the module), which cause the system to be deactivated and the warning light to be illuminated, but will not provide a diagnostic flashout code.
In most cases, the code will be lost if the vehicle is shut off. In other cases, the code may reappear when the vehicle is restarted, or the vehicle may have to be driven to reproduce the problem. If the problem was associated with an intermittent condition, it may be difficult to reproduce. Whenever possible, the code should be read before the vehicle is shut off.
If the red brake light is also on, due to a grounding of the fluid level circuit (perhaps low brake fluid), no flashout code will be flashed and the anti-lock warning lamp will remain on steadily. If there is more than one system fault, only the first recognized code may be obtained.
A flashout code may be obtained only when the anti-lock warning light is on. No code will be flashed when the system is OK.
To check the anti-lock warning light for normal operation, insert the key in the ignition lock and turn it to the ON or START positions. The light should perform a self-check, glowing for about two seconds.
To obtain the flashout code, keep the ignition key in the ON position.
- Locate the diagnostic connector. On pickups and MPVs, the blue three pin connector is located in the left of the engine compartment. See the illustration for Navajo connector, which is located on the main wire bundle inside of cab under the dash, slightly rearward driver side.
- Attach a jumper wire to the terminal C. On pickups, the yellow wire; on MPVs, the gray/white wire.
- On Navajo models, attach a jumper wire to the connector with the black/orange wire.
- Momentarily ground the jumper to the chassis. When the ground is made and broken, the anti-lock warning lamp should begin to flash.
A flashing pattern consists of short flashes and ends with a long flash. Count the short flashes and include the long flash in the count. A same flashing pattern repeats until the ignition switch is turned OFF. Count the flash sequence several times to verify the number of flashes.
Use caution when disassembling any hydraulic components as the system will contain residual pressure. Cover the area around the component to be removed with a shop cloth to catch any brake fluid spray. Do not allow brake fluid to come in contact with painted surfaces.