Test 12L - Bus Bias Level Or Bus (+/-) Open

WARNING: This page is about a different car, the 1995 Dodge Stratus and 1995 Chrysler Cirrus. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagrams, see appropriate article in ENGINE PERFORMANCE:

WIRING DIAGRAMS - 2.0L & 2.4L

After each repair, perform TEST VER-1.

CAUTION: Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.

NOTE: Ignition off during bus test is most common cause for this trouble code.

If ignition was off during BUS test, turn ignition on, engine off. If ignition was on during BUS test, leave scan tool connected. Using an external voltmeter, check voltage between chassis ground and Data Link Connector (DLC) terminal No. 3 (Violet/Gray wire). If voltage is not 2.3-2.6 volts, go to step 3).
If voltage is 2.3-2.6 volts, check voltage between chassis ground and DLC terminal No. 11 (White/Dark Green wire). If voltage is not 2.3-2.6 volts, go to next step. If voltage is 2.3-2.6 volts, replace scan tool cable or scan tool as necessary.
Gain access to Instrument Panel (I/P) 22-pin connector at Body Control Module (BCM). With BCM and BCM connectors connected, back-jumper a wire between I/P 22-pin connector terminal No. 8 (Violet/Gray wire) and chassis ground. See Figure . Using scan tool, perform BUS test. If scan tool does not display BUS SHORT TO GROUND, repair open Violet/Gray wire.
If scan tool displays BUS SHORT TO GROUND, back-jumper a wire between I/P 22-pin connector terminal No. 13 (White/Dark Green wire) and chassis ground. If scan tool does not display BUS SHORT TO GROUND, repair open White/Dark Green wire.

If scan tool displays BUS SHORT TO GROUND, turn ignition off. Disconnect and remove BCM from junction block. Using an external ohmmeter, check resistance between BUS (+) & BUS (-) circuits at I/P 22-pin connector (at BCM). See BUS (+) & BUS (-) CIRCUITS TERMINAL IDENTIFICATION table. If resistance is not 100-140 ohms in all combinations, replace BCM.

BUS (+) & BUS (-) CIRCUITS TERMINAL IDENTIFICATION

Terminal No.	Wire Color	Function
Instrument Panel 22-Pin Connector
8	VIO/GRY	BUS (+)
9	VIO	BUS (+)
10	VIO/BRN	BUS (+)
11	WHT/DK BLU	BUS (-)
12	WHT/BLK	BUS (-)
13	WHT/DK GRN	BUS (-)
Engine 14-Pin Connector
1	VIO/DK GRN	BUS (+)
2	VIO/BRN	BUS (+)
13	WHT/BLK	BUS (-)
14	WHT/DK GRN	BUS (-)

If resistance is 100-140 ohms in all combinations, check resistance between BUS (+) & BUS (-) circuits at engine 14-pin connector (at BCM). See Figure . See BUS (+) & BUS (-) CIRCUITS TERMINAL IDENTIFICATION table. If resistance is not 100-140 ohms in all combinations, replace BCM.
If resistance is 100-140 ohms in all combinations, turn ignition on, engine off. Using scan tool in voltmeter mode, check voltage on junction block internal 12-pin connector terminal No. 2. See Figure . If voltage is less than 10 volts, repair fused B (+) circuit as necessary.
If voltage is more than 10 volts, check voltage on junction block internal 12-pin connector terminal No. 6. If voltage is less than 10 volts, repair open fused ignition switch output circuit.
If voltage is more than 10 volts, use scan tool in ohmmeter mode to check resistance of junction block internal 12-pin connector terminal No. 10. If resistance is more than 15 ohms, repair open ground circuit as necessary. If resistance is less than 15 ohms, replace BCM.