1999 GMC Jimmy Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1999 GMC Jimmy
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1999 GMC Jimmy ProblemsCheck Engine Light With Code P1870
Vehicles equipped whit a 4 speed automatic transmission may develop a harsh 1-2 shift and/or illumination of the Check Engine Light with code P1870 stored. This can be caused by wear of the bore for the TCC isolator and regulator valves in the valve body. This condition does not commonly occur until the transmission reaches normal operating temperature. If the valve body is worn, replacement will be necessary to correct this concern.
It is common for the fuel level sensor in the fuel tank read the fuel level incorrectly. The sensor must be replaced to correct the condition. Our technicians recommend having the complete fuel pump module replaced on high mileage vehicles.
1999 GMC Jimmy Questions99' JIMMY 4.3 My 4wd was serviced and HAD FRONT DIFF. AND TRANSFER CASE REPLACED. now the service4x4, light is lot up full-time and 4 button selector , has no lights at all, EVER! (1 answer)
Just put speed sensors in transfer case, already . it went in for probs. W/ Jimmy not selecting w/ 4wd or2wd ID like
Then it would self cancel and after a while of clicking , would shut down and service 4wd would light up on dashboard
Just did full tune up . gas gauge hasn't worked for a year. Issue w/ bucking and nearly stalling,was mostly eliminated. But was the root cause , of my fuel pump exchange. Still no gauge . did coil.tps as well
Pimp pressure of old pump was holding near 50 psi. Borderline I thought..any volt ...