Jeep Wagoneer/Commando/Cherokee 1984-1998

Electronic Control Unit (ECU)


The Electronic Control Unit (ECU) was utilized on the 1995-96 models. The Hydraulic Control Unit (HCU) on 1997-98 Jeep models has a Controller Antilock Brakes (CAB) unit mounted to it, which serves the same function as the ABS-ECU.

Removal & Installation

See Figure 1

The Electronic Control Unit (ECU) is usually located in the engine compartment, mounted on the driver's side inner fender panel.

  1. Turn the ignition to the OFF position.
  3. Remove the lower finish panel from the instrument panel.
  5. Remove the ECU retaining bolts/nuts and release the metal strap that secures the ECU harness connector to the pin terminals.
  7. Disengage the harness connector from the ECU. This is achieved by tilting the connector upward to disengage it from the pins and then sliding it out of the retaining tangs.
  9. Remove the ECU and mounting bracket as an assembly.

Click image to see an enlarged view

Fig. Fig. 1: Releasing the ECU harness connector strap-1995 model shown

To install:
  1. If a new ECU is to be installed, first install the mounting bracket on the ECU and tighten the fasteners to 85-125 inch. lbs (10-14 Nm).

Use care when connecting the harness connector to the ECU, the pins may be easily damaged.

  1. Engage the harness connector to the ECU making sure it is fully seated and engages the tangs on the ECU.
  3. Position the ECU bracket under the dash and install the retainers. Tighten the retainers to 75-125 inch lbs. (8-14 Nm).
  5. Install the finish panel on the instrument panel.