Diagnostic Aids

WARNING: This page is about a different car, the 1995 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test when directed by QUICK TEST procedure. This CIRCUIT TEST is intended to diagnose:

Wiring harness circuit KS.

Fig 1: Identifying KS Circuit & Connector Terminals

KS CIRCUIT INFORMATION

Circuit

PCM Pin No.

⁽¹⁾ BOB Pin No.

Wire Color

White

⁽¹⁾	Rotunda Breakout Box (007-00033).

1) Check PCM Input Signal Turn ignition off. Install Breakout Box (007-00033). Connect PCM to breakout box. Start engine and allow to idle. Measure voltage between breakout box test pin No. 23 and ground. If voltage is not about 2.5 volts, go to next step. If voltage is about 2.5 volts, input signal is okay. Repeat QUICK TEST. If Code 34 is still present, replace PCM.

2) Check KS Circuit Turn ignition off. Disconnect PCM from breakout box. Disconnect KS wiring harness connector. Measure resistance between test pin No. 23 and KS terminal of knock sensor wiring harness connector. Resistance should be 5 ohms or less. Measure resistance between breakout box test pin No. 23 and ground. Resistance should be 10,000 ohms or more. If resistance is as specified, go to next step. If resistance is not as specified, repair or replace KS circuit as necessary.

3) Check KS In-Line Connector Ground Turn ignition off. Disconnect knock sensor in-line connector. Measure resistance between in-line harness connector Black/Red wire terminal and ground. If resistance is less than 5 ohms, replace knock sensor. If resistance is 5 ohms or more, repair or replace Black/Red wire circuit as necessary.