Onstar(R) - Red LED/DTC B2470/Unable To Connect

SOURCE: Isuzu Service News

TITLE: Intermittent Red LED, DTC B2470 and Unable to Contact OnStar Center

APPLIES TO: 03-05 Ascender

SERVICE TIP:

Condition:

Some OnStar customers may report an intermittent red LED and are unable to use their OnStar system. The vehicle may have a current or history DTC B2470 present in the OnStar module due to possible corrosion or poor connection at the antenna base or coupler box.

Correction:

Prior to performing step two of the Service Manual for the B2470 DTC, the cellular coax should be disconnect at the VCU/VCIM with the coax cable still connected to the base.

Measure from the center pin to the shield to identify possible high resistance in the cable or base. Glass mount should read 1 Ohm or less, roof mount 995 Ohms.

If measurements are out of specification disconnect the cellular coax at the antenna base. Measure coax cable from center pin to center pin (should read 1 Ohm or less) and center pin to shield (should read OL)

If cellular coax measurements are within specification, inspect base or coupler box for damage, corrosion, and replace if necessary.

DTC should be cleared with the Tech 2 and retest the system to ensure repair is complete.

Notice: Glass mount antenna couplers should NOT be installed over any aftermarket window tint.

To determine if the VCIM is the cause of the B2470, install a jumper wire into the center pin of the cellular antenna connector at the VCIM and ground it to the case. Install unit and power up the vehicle, if the B2470 goes to history, the VCIM is working as designed, and the antenna and coax cable should be serviced or replaced as needed.