Reading Codes

NAVAJO & 1994 B SERIES PICK-UP MODELS

Scan Tool Method

1. Connect the scan tool to the self-test connectors. Make certain the test button is unlatched or up.
2. Start the engine and run it until normal operating temperature is reached.
3. Turn the engine OFF and wait 10 seconds.
4. Activate the test button on the STAR tester.
5. Turn the ignition switch ON but do not start the engine.
6. The codes will be transmitted. Six to nine seconds after the last code, a single separator pulse will be transmitted. Six to nine seconds after this pulse, the codes from the Continuous Memory will be transmitted.
7. Record all service codes displayed. Do not depress the throttle during the test.
8. After the test, compare the DTC's retrieved with the accompanying DTC identification charts.

Analog Voltmeter Method

In the absence of a scan tool, an analog voltmeter may be used to retrieve stored fault codes. Set the meter range to read DC 0–15 volts. Connect the positive lead of the meter to the battery positive terminal and connect the negative lead of the meter to the Self-Test Output (STO) pin of the diagnostic connector.

Follow the directions given previously for performing the scan tool procedure. To activate the procedure, use a jumper wire to connect the signal return pin on the diagnostic connector to the self-test input connector. The self-test input line is the separate wire and connector with or near the diagnostic connector.

The codes will be transmitted as groups of needle sweeps. This method may be used to read either 2 or 3 digit codes. The Continuous Memory codes are separated from the other codes by 6 seconds, a single sweep and another 6 second delay.

1. After the test, compare the DTC's retrieved with the accompanying DTC identification charts.

Malfunction Indicator Lamp (MIL) Method

The Malfunction Indicator Lamp (MIL) on the dashboard may also be used to retrieve the stored codes. This method displays only the stored codes and does not allow any system investigation. It should only be used in field conditions where a quick check of stored codes is needed.

Follow the directions given previously for performing the scan tool procedure. To activate the tests, use a jumper wire to connect the signal return pin on the diagnostic connector to the Self-Test Input (STO) connector. The self-test input line is the separate wire and connector with or near the diagnostic connector.

Codes are transmitted by place value with a pause between the digits; Code 32 would be sent as 3 flashes, a pause and 2 flashes. A slightly longer pause divides codes from each other. Be ready to count and record codes; the only way to repeat a code is to recycle the system. This method may be used to read either 2 or 3 digit codes. The Continuous Memory codes are separated from the other codes by 6 seconds, a single flash and another 6 second delay.