DTC P1698: NO BUS MESSAGES RECEIVED FROM PCM

Monitor & Set Conditions

PCM is monitored for receiving BUS messages with ignition on and engine off and with engine running. DTC may set if there is no communication with the PCM.

Possible Causes

• No Response To PCM
• Open CCD BUS Circuit From PCM To Data Link Connector
• Open CCD BUS (-) Circuit From PCM To Data Link Connector
• Open Ground Circuit
• PCM

Testing

1. Turn ignition on with engine off. Using DRBIII(R) scan tool, try to read DTCs or sensors in PCM. If scan tool does not display NO RESPONSE to PCM, go to next step. If scan tool displays NO RESPONSE to PCM, go to NO RESPONSE FROM PCM under SCAN TOOL COMMUNICATIONS.

2. Ensure ignition is on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the BUS operational test will be performed automatically. If scan tool does not display BUS OPERATIONAL, go to next step. If scan tool
displays BUS OPERATIONAL, test is complete.

3. Ensure ignition is on with engine off. Using scan tool, clear DTCs from Engine Control Module (ECM). Turn ignition off and then back on again with engine off. Using scan tool, check for stored DTCs in ECM. If DTC P1698 exists, go to next step. If DTC P1698 does not exist, test is complete.

4. Turn ignition off. Disconnect harness PCM connectors. PCM is located at passenger's side rear corner of engine compartment. Check for poor connection/terminal contact at PCM harness connectors. Repair as necessary. Connect jumper wire between ground and terminal No. 30 (Violet/Brown wire) on PCM harness connector C3. Turn ignition on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the BUS operational test will be performed automatically. If scan tool displays SHORT TO GROUND, remove jumper wire and go to next step. If scan tool does not display SHORT TO GROUND, remove jumper wire. Repair open in Violet/Brown wire between PCM and Data Link Connector (DLC) terminal No. 3.

5. Turn ignition off. Ensure PCM harness connectors are still disconnected. Connect jumper wire between ground and terminal No. 28 (White/Black wire) on PCM connector C3. Turn ignition on with engine off. Using scan tool, select BODY and select type of instrument cluster that vehicle is equipped with. Once type of instrument cluster is selected, the BUS operational test will be performed automatically. If scan tool displays SHORT TO GROUND, remove jumper wire and go to next step. If scan tool does not display SHORT TO GROUND, remove jumper wire. Repair open in White/Black wire between PCM and DLC terminal No. 11.

6. Turn ignition off. Ensure PCM harness connectors are still disconnected. Using DVOM, measure resistance between ground and terminal No. 31 (Black/Tan wire) on PCM connector C1. If resistance is less than 10 ohms, replace and program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If resistance is 10 ohms or greater, repair open in Black/Tan wire between PCM and ground connection. Ground connection is located at ground connection for negative battery terminal.